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Chore: re-organized to only have folders relevant to benchmarking

This commit is contained in:
Richard Wong 2024-05-06 16:21:09 +09:00
parent aa3c3e3b20
commit 850255fab2
Signed by: richard
GPG Key ID: 72948FBB6D359A6D
8 changed files with 1 additions and 1825 deletions
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6
.gitignore vendored
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.vscode
deferred_planarity_test/build
make_graphs/bin
make_graphs/test_graphs
make_planar/bin
test_area
dpt
# remove build intermediate files
deferred_planarity_test/obj/
deferred_planarity_test/bin/
graph_datasets

1
README.md
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This branch tests the idea of using fuzzing to choose the direction of mutation

215
deferred_planarity_test/include/mps.h
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//-----------------------------------------------------------------------------------
// Header for modules: mps.cpp, mps_test.cpp, node.cpp.
//-----------------------------------------------------------------------------------
#ifndef _MPS_H
#define _MPS_H
#include <iostream>
#include <fstream>
#include <vector>
#include <utility>
#include <climits>
#include <limits>
#include <random>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <ogdf/fileformats/GraphIO.h>
using namespace std;
class node;
class maximal_planar_subgraph_finder;
enum label {
NOT_VISITED = 0,
ARTIFICIAL_EDGE = 1,
BOUNDARY_PATH = 2,
DELETED = 3
};
enum node_type {
P_NODE = 0,
C_NODE = 1,
REPLICA_NODE = 2,
AE_VIRTUAL_ROOT = 3
};
class node
{
public:
//CONSTRUCTOR
node(node_type t);
//DESTRUCTOR
~node() {}
//TYPE, ID, INDEX
node_type type();
int post_order_index();
void set_id(int i);
void set_post_order_index(int i);
void recursively_labeling();
int node_id();
//DFS-TREE
void add_adj(node* n);
int degree();
node* adj(int i);
void set_adj_list(vector<node*> vec);
void DFS_visit(vector<node*> &dfsList, int &index);
void guided_DFS_visit(vector<node *> &dfsList,
const vector<node *> &node_list,
int &return_index,
const unordered_map<int, int> &node_id_to_pos);
void mutated_DFS_visit(vector<node *> &dfsList,
const vector<node *> &node_list,
int &index,
int &traversal_index,
const unordered_map<int, int> &node_id_to_pos,
int mutate_point,
mt19937 rng);
// custom comparator function to sort nodes according to order in given vector
bool sortByOrder(const unordered_map<int, int>& node_id_to_pos, node* a, node* b);
//PARENT-CHILDREN
void set_parent(node* n) ;
node* parent();
int child_num();
node* child(int i);
void add_child(node* n);
void clear_children();
void remove_child(int i);
void remove_child(node* n);
vector<node*>* get_children_list();
//BOUNDARY_PATH
void set_to_boundary_path(node* n0, node* n1);
void set_neighbor(int i, node* n);
void set_neighbor(node* u, node* v);
node* neighbor(int i);
node* get_next(node* prev);
//ARTIFICIAL EDGE
node* AE(int i);
void set_AE(int i, node* j);
void add_AE(node* j);
void inherit_AE(node* u);
void init_AE(node* u);
//REPLICA
node* original_node();
node* get_c_node();
void set_c_node(node* c);
bool is_sentinel();
static bool is_same(node* n1, node* n2);
void init_replica(node* u, node* c);
//LABELING
void set_1st_label(int i);
void set_2nd_label(label i);
int get_1st_label();
label get_2nd_label();
//C-NODE
node* get_a_list_node();
int c_node_size();
node* essential(int i);
void clear_essential();
void add_essential(node* u);
//MARK
void mark();
static void init_mark();
void un_mark();
bool is_marked();
private:
//Basic information.
node_type _type;
pair<int, label> _label;
//Information about neighborhood.
node* _neighbor[2];
node* _AE_root[2];
//Information about higher hierarchy.
node* _original_node;
node* _c_node;
//Information about parent-children relation.
node* _parent;
vector<node*> _children;
//Information about about p-nodes in DFS-tree
vector<node*> _adj_list;
int _post_order_index;
int _node_id;
//List of essential nodes in c-node
vector<node*> _essential_list;
//Mark
int _mark;
static int _ref_mark;
};
class maximal_planar_subgraph_finder
{
public:
maximal_planar_subgraph_finder();
~maximal_planar_subgraph_finder();
// functions that prepare state
void init_from_graph(const ogdf::Graph &G);
vector<int> generate_post_order(const ogdf::Graph &G);
vector<int> generate_mutated_post_order(const ogdf::Graph &G, const vector<int> &post_order, int mutate_point);
vector<int> generate_guided_post_order(const ogdf::Graph &G, const vector<int> &post_order);
void postOrderTraversal();
void guidedPostOrderTraversal(const vector<int> &post_order);
void mutatedPostOrderTraversal(const vector<int> &post_order, int mutate_point);
// compute_mps combines functionality to reduce repeating object initialization
// the results are returned by modifying mutable reference
void compute_mps(const ogdf::Graph &G, int mutate_point, vector<int> &post_order, int &return_edge_size);
int find_mps(const ogdf::Graph &G);
int compute_removed_edge_size(const ogdf::Graph &G, vector<int> post_order);
node* get_new_node(node_type t);
void reset_state();
int output_removed_edge_size();
vector<int> return_post_order();
// void set_post_order(vector<int> post_order);
void print_post_order();
void sort_adj_list();
void determine_edges();
void back_edge_traversal();
bool back_edge_traversal(node* traverse_node, int index);
void make_essential(node* p_node, node* c_node);
node* find(node* n);
void merge(pair<pair<node*, node*>, pair<node*, node*> > boundary, node* list_node);
void eliminate(node* u);
void eliminate_AE(node* u, node* v);
pair<pair<node*, node*>, pair<node*, node*> > trim(node* u);
void c_node_extension(node* c_node);
void recursively_shaving(node* u);
pair<node*, node*> shave(node* x);
pair<node*, node*> parallel_search_sentinel(node* x, node* &c);
pair<node*, node*> parallel_search_sentinel(node* n0, node* n0_prev, node* n1, node* n1_prev, node* & c);
pair<node*, node*> count_sentinel_elimination(pair<node*, node*> sentinel_1, int num_sentinel);
node* construct(node* u);
node* construct(node* c, node* p);
void parenting_labeling_shaving(node* u, node* node_i) ;
private:
vector<node*> _node_list; //List of nodes input.
vector<pair<node*, node*> > _edge_list; // Edges in DFS-tree. These edges must be contained in the maximal planar subgraph that we found.
vector<node*> _post_order_list; //The sorted version (increasing with post-order-index) of _node_list.
vector<pair<node*, node*> > _back_edge_list; // Edges other than that in DFS-tree. (The first node's index is higher than the second's.)
vector<bool> _is_back_edge_eliminate; //Record that if the back-edge has been eliminated or not.
vector<node*> _new_node_list; //Newly added nodes.
};
#endif // for MPS_H

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deferred_planarity_test/makefile
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SRC_DIR := src
OBJ_DIR := obj
BIN_DIR := bin
TARGET := $(BIN_DIR)/dpt_planarizer
SRCS := $(wildcard $(SRC_DIR)/*.cpp)
OBJS := $(SRCS:$(SRC_DIR)/%.cpp=$(OBJ_DIR)/%.o)
DEPS := $(OBJS:.o=.d)
# compiler and flags
CXX := g++
CPPFLAGS := -Iinclude -MMD -MP
CXXFLAGS := -std=c++14 -Wall
LDFLAGS := -lOGDF
build: $(TARGET)
# build target executable
$(TARGET): $(OBJS) | $(BIN_DIR)
$(CXX) $^ -o $@ $(LDFLAGS)
# compile source to object files
$(OBJ_DIR)/%.o: $(SRC_DIR)/%.cpp | $(OBJ_DIR)
$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
$(BIN_DIR) $(OBJ_DIR):
mkdir -p $@
# include dependency files
-include $(DEPS)
.PHONY: clean
clean:
rm -r $(OBJ_DIR)

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deferred_planarity_test/src/main.cpp
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//-----------------------------------------------------------------------------------
// A simple code that test the MPS algorighm.
//-----------------------------------------------------------------------------------
#include "mps.h"
#include <iostream>
#include <cstdlib>
#include <climits>
#include <string>
#include <algorithm>
#include <iterator>
#include <random>
#include <vector>
#include <ogdf/fileformats/GraphIO.h>
#define START_TEMP 100
// #define TIME
using namespace std;
int compute_removed_edge_size(const ogdf::Graph &G, vector<int> post_order);
// these functions are defined in mps_test.cpp
// but their signatures are not in mps.h, hence they are declared here
ogdf::Graph read_from_gml(string input_file);
vector<int> generate_post_order(const ogdf::Graph &G);
vector<int> generate_mutated_post_order(const ogdf::Graph &G, vector<int> post_order, int mutate_point);
vector<int> generate_guided_post_order(const ogdf::Graph &G, vector<int> post_order);
void compute_mps(const ogdf::Graph &G, int mutate_point, vector<int> &post_order, int &return_edge_size);
void vector_printer(const vector<int>& state) {
for (size_t i = 0; i < state.size(); ++i) {
std::cout << state[i] << ",";
}
std::cout << std::endl;
}
vector<int> repeated_mutation(const ogdf::Graph &G, int k_max) {
// generate first post order
// std::cout << "generate first post order" << std::endl;
vector<int> old_order = generate_post_order(G);
vector_printer(old_order);
vector<int> temp_order = old_order;
int new_removed_size;
int old_removed_size = INT_MAX;
// prepare random selection
std::random_device rd;
std::mt19937 gen{rd()}; // seed the generator
int first_value = 0;
// we want the index of the third last value
// at a given traversal index, only the next iteration has the mutated value
int last_value = (old_order.size() - 1) - 2;
std::uniform_int_distribution<> dist{first_value, last_value}; // set min and max
for (int k = 0; k < k_max; ++k) {
// function compute new post_order and new_removed_size
// temp_order and new_removed_size will be updated with new values
#ifdef TIME
auto start = std::chrono::high_resolution_clock::now();
#endif
compute_mps(G, dist(gen), temp_order, new_removed_size);
#ifdef TIME
auto end = std::chrono::high_resolution_clock::now();
std::cout << "compute_mps: " << std::chrono::duration_cast<std::chrono::microseconds>(end - start).count() << std::endl;
#endif
// if there is an improvement
// 1. update the removed size to use the new smaller size
// 2. update the old_order to be the new_order
if (new_removed_size < old_removed_size) {
old_removed_size = new_removed_size;
old_order = temp_order;
// if there is no improvement, we revert the temp_order to the old_order
} else {
temp_order = old_order;
}
}
return old_order;
}
//-----------------------------------------------------------------------------------
// Main function.
//-----------------------------------------------------------------------------------
int main(int argc, char* argv[]) {
string input_file = argv[1];
int k_max = std::stoi(argv[2]);
const ogdf::Graph G = read_from_gml(input_file);
// generate order here
vector<int> post_order = repeated_mutation(G, k_max);
// test timing of function
// test_correctness(G);
// // print final order and number of edges
std::cout << "---" << std::endl;
std::cout << "final report" << std::endl;
std::copy(post_order.begin(), post_order.end(), std::ostream_iterator<int>(std::cout, ","));
std::cout << std::endl;
int removed_edges = compute_removed_edge_size(G, post_order);
std::cout << "Number of removed edges: " << removed_edges << std::endl;
return 0;
}

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deferred_planarity_test/src/mps.cpp
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//-----------------------------------------------------------------------------------
// Implementation of a MPS algorithm via PC-tree.
//-----------------------------------------------------------------------------------
#include "mps.h"
// #define DEBUG
// constructor can be made empty
maximal_planar_subgraph_finder::maximal_planar_subgraph_finder() {}
//Destructor
maximal_planar_subgraph_finder::~maximal_planar_subgraph_finder() {
for (size_t i = 0; i < _node_list.size(); ++i) delete _node_list[i];
for (size_t i = 0; i < _new_node_list.size(); ++i) delete _new_node_list[i];
}
node*
maximal_planar_subgraph_finder::get_new_node(node_type t) {
_new_node_list.push_back(new node(t));
return _new_node_list[_new_node_list.size()-1];
}
vector<int>
maximal_planar_subgraph_finder::return_post_order() {
vector<int> post_order;
// we have arg number of elements
post_order.reserve(_post_order_list.size()); // reserve for decreased reallocation
for (size_t i = 0; i < _post_order_list.size(); ++i) {
post_order.push_back(_post_order_list[i]->node_id());
}
return post_order;
}
//Determine the post-order-list by a DFS-traversal.
void
maximal_planar_subgraph_finder::postOrderTraversal() {
node::init_mark();
// always start with node 0
int postOrderID = 0;
for (size_t i = 0; i < _node_list.size(); ++i) {
if (!_node_list[i]->is_marked()) {
_node_list[i]->DFS_visit(_post_order_list, postOrderID);
}
}
}
// Determine the post-order-list by a DFS-traversal.
// take in a post-order argument then traces the graph in the same order
// return is by reference via _post_order_list
void
maximal_planar_subgraph_finder::guidedPostOrderTraversal(const vector<int> &post_order) {
node::init_mark();
// // implementation 1: pass reversed vector
// vector<int> rev_post_order;
// for (int i = post_order.size() - 1; i >= 0; --i) {
// rev_post_order.push_back(post_order[i]);
// }
// int start = rev_post_order[0];
// implementation 2: use unordered_map to map node_id to position in reversed post_order
unordered_map<int, int> node_id_to_pos;
node_id_to_pos.reserve(post_order.size());
int j = 0;
// we flip the post_order vector around
for (size_t i = post_order.size() - 1; i != std::numeric_limits<size_t>::max(); --i) {
node_id_to_pos[post_order[i]] = j++;
}
int postOrderID = 0;
int end_condition = _node_list.size();
// we start from the end of the post_order, which is the root node
int start = post_order[post_order.size() - 1];
int i = start;
// reserve for _post_order_list to decrease reallocation
_post_order_list.reserve(_node_list.size());
while (true)
{
if (((start > 0) && (i == (start - 1))) || ((start == 0 ) && (i == end_condition - 1)))
{
if (!_node_list[i]->is_marked())
{
_node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, node_id_to_pos);
}
break;
}
if (!_node_list[i]->is_marked())
{
_node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, node_id_to_pos);
}
i = (i + 1) % end_condition;
}
}
//Determine the post-order-list by a DFS-traversal.
// take in a post-order argument then traces the graph in the same order
// return is by reference via _post_order_list
void
maximal_planar_subgraph_finder::mutatedPostOrderTraversal(const vector<int> &post_order, int mutate_point) {
node::init_mark();
// // implementation 1: use vector
// vector<int> rev_post_order;
// for (size_t i = post_order.size() - 1; i != std::numeric_limits<size_t>::max(); --i) {
// rev_post_order.push_back(post_order[i]);
// }
// implementation 2: use unordered_map to map node_id to position in reversed post_order
unordered_map<int, int> node_id_to_pos;
node_id_to_pos.reserve(post_order.size());
int j = 0;
// we flip the post_order vector around
for (size_t i = post_order.size() - 1; i != std::numeric_limits<size_t>::max(); --i) {
node_id_to_pos[post_order[i]] = j++;
}
int postOrderID = 0;
int traversal_index = 0;
// setup random rng function
std::random_device rd;
std::mt19937 rng{rd()};
int start = 0;
// if we mutate first node, we will select a random starting node
if (mutate_point == 0) {
int first_value = 0;
int last_value = post_order.size() - 1;
std::uniform_int_distribution<> dist{first_value, last_value};
start = post_order[dist(rng)];
// if we don't mutate first, we just use the root node of the post_order
} else {
start = post_order[post_order.size() - 1];
}
// set loop variables
int i = start;
// reserve for _post_order_list to decrease reallocation
_post_order_list.reserve(_node_list.size());
int end_condition = _node_list.size();
// this loop assumes start is not from 0
// if starting index is not 0, it just increments and loops around until it encounters the element before it
while (true)
{
if (((start > 0) && (i == (start - 1))) || ((start == 0 ) && (i == end_condition - 1)))
{
if (!_node_list[i]->is_marked())
{
_node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, traversal_index, node_id_to_pos, mutate_point, rng);
}
break;
}
if (!_node_list[i]->is_marked())
{
_node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, traversal_index, node_id_to_pos, mutate_point, rng);
}
i = (i + 1) % end_condition;
}
}
void
maximal_planar_subgraph_finder::print_post_order() {
int current_index;
for (size_t i = 0; i < _post_order_list.size(); ++i) {
current_index = _post_order_list[i]->node_id();
std::cout << current_index << ",";
}
std::cout << std::endl;
}
// this function is not used anywhere
//Set the post-order-list via given list
// void
// maximal_planar_subgraph_finder::set_post_order(vector<int> post_order) {
// for (int i = 0; i < _node_list.size(); ++i) {
// _node_list[i]->set_post_order_index(post_order[i]);
// }
// }
//Sort the adj-list of every node increasingly according to post-order-index.
void
maximal_planar_subgraph_finder::sort_adj_list() {
vector<vector<node*> > vecList;
vecList.resize(_post_order_list.size());
for (size_t i = 0; i < _post_order_list.size(); ++i) {
for (int j = 0; j < _post_order_list[i]->degree(); ++j) {
vecList[_post_order_list[i]->adj(j)->post_order_index()].push_back(_post_order_list[i]);
}
}
for (size_t i = 0; i < _post_order_list.size(); ++i) {
_post_order_list[i]->set_adj_list(vecList[i]);
}
}
//Determine edge-list, and back-edge-list.
//Order the edges properly.
void
maximal_planar_subgraph_finder::determine_edges() {
for (size_t i = 0; i < _post_order_list.size(); ++i) {
if (_post_order_list[i]->parent() == 0) continue;
_post_order_list[i]->set_1st_label(_post_order_list[i]->parent()->post_order_index());
_edge_list.push_back(pair<node*, node*> (_post_order_list[i]->parent(), _post_order_list[i]));
}
for (size_t i = 0; i < _post_order_list.size(); ++i) {
for (int j = 0; j < _post_order_list[i]->degree(); ++j) {
if (_post_order_list[i]->adj(j)->post_order_index() > static_cast<int>(i)) break;
if (_post_order_list[i]->adj(j)->get_1st_label() == static_cast<int>(i)) continue;
_back_edge_list.push_back(pair<node*, node*> (_post_order_list[i], _post_order_list[i]->adj(j)));
_is_back_edge_eliminate.push_back(false);
}
}
for (size_t i = 0; i < _post_order_list.size(); ++i) {
_post_order_list[i]->set_1st_label(INT_MAX);
}
}
//The main part of the whole algorithm: Back-edge-traversal
void
maximal_planar_subgraph_finder::back_edge_traversal() {
node* i_node = 0;
node* current_node = 0;
for (size_t i = 0; i < _back_edge_list.size(); ++i) {
current_node = _back_edge_list[i].second;
i_node = _back_edge_list[i].first;
if (!back_edge_traversal(current_node, i_node->post_order_index())) _is_back_edge_eliminate[i] = true;
}
}
//sub-function for the for-loop of back_edge_traversal().
bool maximal_planar_subgraph_finder::back_edge_traversal(node* traverse_node, int index) {
node* parent_node; //The next node to traverse.
//If the node has been deleted.
if (traverse_node == 0 || traverse_node->get_2nd_label() == DELETED) {
return false;
}
//We have reached the i-node, stop.
if (traverse_node->post_order_index() == index) {
return true;
}
//Case 1
if (traverse_node->get_2nd_label() == NOT_VISITED) {
//1.1
if (traverse_node->get_1st_label() == INT_MAX) {
traverse_node->set_1st_label(index);
parent_node = traverse_node->parent();
}
//1.2
else if (traverse_node->get_1st_label() == index) {
return true;
}
//1.3
else if (traverse_node->get_1st_label() < index) {
parent_node = construct(traverse_node);
traverse_node->set_1st_label(index);
}
}
//Case 2: Find the top-tier c-node.
else {
node* my_c_node = find(traverse_node);
make_essential(traverse_node, my_c_node);
//2.1
if (my_c_node->get_1st_label() == index) {
parent_node = my_c_node;
}
//2.2
else if (my_c_node->get_1st_label() < index) {
node* my_c_node_2 = construct(my_c_node, traverse_node);
parent_node = my_c_node_2;
}
traverse_node->set_1st_label(index);
traverse_node->set_2nd_label(NOT_VISITED);
}
if (back_edge_traversal(parent_node, index)) {
if (parent_node != _post_order_list[index]) parent_node->add_child(traverse_node);
return true;
}
else {
eliminate(traverse_node);
return false;
}
}
//The p_node is originally a normal node in c_node's boundary cycle.
//Now we transfer it to be an essential node by the following steps:
//1. Create a replica-node of p_node to be representative of p_node in c_node.
//2. Take out the p_node from c_node, and then set the parent of p_node to be c_node.
//Note: We are not adding p_node to the c_node's children-list.
void
maximal_planar_subgraph_finder::make_essential(node* p_node, node* c_node) {
node* sentinel = get_new_node(REPLICA_NODE);
node* n0 = p_node->neighbor(0);
node* n1 = p_node->neighbor(1);
sentinel->init_replica(p_node, c_node);
c_node->add_essential(sentinel);
sentinel->set_to_boundary_path(n0, n1);
sentinel->inherit_AE(p_node);
n0->set_neighbor(n0->get_next(p_node), sentinel);
n1->set_neighbor(n1->get_next(p_node), sentinel);
p_node->set_neighbor((node*)0, (node*)0);
p_node->set_parent(c_node);
}
//Find the top-tier c-node of the input node.
//Note: We don't set the input node to be essential node of the top-tier c-node.
//When terminated, the input node will be in the boundary cycle of top-tier c-node.
node* maximal_planar_subgraph_finder::find(node* n) {
pair<pair<node*, node*>, pair<node*, node*> > boundary;
node* c_node_new = 0;
int c_node_size = 0;
node* return_node = 0;
if (n->parent() == 0) {
//If n is already a node in boundary cycle.
//Note: n must not be an essential node, otherwise it will never enter the function.
//Find the first(nearest to n) essential node.
boundary.first = parallel_search_sentinel(n, c_node_new);
}
else {
//If n is not a node in boundary cycle.
//It is in an Artificial edge.
//Trim it.
boundary = trim(n);
//Find the first(nearest to n) essential node.
boundary.first = parallel_search_sentinel(boundary.first.first, boundary.first.second, boundary.second.first, boundary.second.second, c_node_new);
}
//Find the c-node in the current hierachy .
//If it is top-tier, return it.
if (c_node_new != 0) return c_node_new;
c_node_new = (boundary.first).first->get_c_node();
//If not, find the two nearest essential node, eliminate the rest nodes.
c_node_size = c_node_new->c_node_size();
boundary.second = count_sentinel_elimination(boundary.first, c_node_size);
//Go to the higher hierachy, and continue to find.
if (c_node_new->get_2nd_label() == ARTIFICIAL_EDGE) {
//A peculiar technic:
//Remove all the children of c_node_new but the one that should remains(Let it be u).
//Remove all other essential nodes, pretend to be a c-node of size equals 2.
//Call find(u).
node* u = 0;
for (int i = 0; i < c_node_new->child_num(); ++i) {
if (node::is_same(boundary.first.first, c_node_new->child(i)) || node::is_same(boundary.second.first, c_node_new->child(i))) {
u = c_node_new->child(i);
}
else eliminate(c_node_new->child(i));
}
c_node_new->clear_children();
c_node_new->add_child(u);
c_node_new->clear_essential();
c_node_new->add_essential(boundary.first.first);
c_node_new->add_essential(boundary.second.first);
return_node = find(u);
}
else return_node = find(c_node_new);
//Merge the part of boundary cycle remains in current hierachy to the top-tier c-node.
merge(boundary, c_node_new);
return return_node;
}
//The list_node is a c-node.
//The boundary indicates the part of the boundary cycle of c-node needs to be merge to the higher hierachy.
//Replace the list_node by boundary.
//Set list_node to be DELETED.
//Note: We do not eliminate anything in this function.
void
maximal_planar_subgraph_finder::merge(pair<pair<node*, node*>, pair<node*, node*> > boundary, node* list_node) {
node* n0 = list_node->neighbor(0);
node* n1 = list_node->neighbor(1);
node* s0, * s0_prev;
node* s1, * s1_prev;
if (node::is_same(boundary.first.first, n0)) {
s0 = boundary.first.first;
s0_prev = boundary.first.second;
s1 = boundary.second.first;
s1_prev = boundary.second.second;
}
else {
s0 = boundary.second.first;
s0_prev = boundary.second.second;
s1 = boundary.first.first;
s1_prev = boundary.first.second;
}
if (s0_prev == s1 && s1_prev == s0) {
n0->set_neighbor(n0->get_next(list_node), n1);
n1->set_neighbor(n1->get_next(list_node), n0);
}
else {
n0->set_neighbor(n0->get_next(list_node), s0_prev);
n1->set_neighbor(n1->get_next(list_node), s1_prev);
s0_prev->set_neighbor(s0_prev->get_next(s0), n0);
s1_prev->set_neighbor(s1_prev->get_next(s1), n1);
}
//Inherit AE.
n0->inherit_AE(s0);
n1->inherit_AE(s1);
//Delete c-node
list_node->set_2nd_label(DELETED);
}
//Set u and its subtree to be DELETED.
//If u has some AE, eliminate them.
//We don't do anything about u's parent, neighborhood.(Only children are affected.)
//If u is a p-node, we don't eliminate anything in the lower hierachy that corresponds to the same p-node.
//If u is a c-node, we eliminate all nodes in u's boundary cycle.
void
maximal_planar_subgraph_finder::eliminate(node* u) {
if (u->get_2nd_label() == DELETED) return;
u->set_2nd_label(DELETED);
if (u->type() == C_NODE) {
node* list_node = u->get_a_list_node();
node* n0, * n0_prev;;
node* temp = 0;
n0 = list_node;
n0_prev = list_node->neighbor(0);
while (true) {
eliminate(n0);
temp = n0;
n0 = n0->get_next(n0_prev);
n0_prev = temp;
if (n0 == list_node) break;
}
}
else if (u->type() == P_NODE) {
for (int i = 0; i < u->degree(); ++i) {
if (u->adj(i)->post_order_index() < u->post_order_index() && u->adj(i)->get_1st_label() == INT_MAX) eliminate(u->adj(i));
}
}
if (u->AE(0) != 0) eliminate(u->AE(0));
if (u->AE(1) != 0) eliminate(u->AE(1));
for (int i = 0; i < u->child_num(); ++i) {
eliminate(u->child(i));
}
}
//Eliminate the AE of(u,v)-link that points to u.(If exists)
void
maximal_planar_subgraph_finder::eliminate_AE(node* u, node* v) {
int v_index = v->post_order_index();
if (u->AE(0) != 0 && u->AE(0)->get_1st_label() == v_index) {
eliminate (u->AE(0));
u->set_AE(0, 0);
}
if (u->AE(1) != 0 && u->AE(1)->get_1st_label() == v_index) {
eliminate (u->AE(1));
u->set_AE(1, 0);
}
}
//The input node u must not be c-node.
//The traversed node is in the AE = (up <- down).
//The returned boundary = [up, up_prev ..., down_prev, down].
//Direction: up it higher than down.
pair<pair<node*, node*>, pair<node*, node*> >
maximal_planar_subgraph_finder::trim(node* u) {
node* up = 0;
node* down = 0;
//Since we may do c-node extension in the future, we need to memorize next in order to deduce prev.
node* up_next = 0;
node* down_next = 0;
node* new_AE_root = 0;
//The index from small to large indicates the path that we traversed, note that u = node_list[0].
vector<node*> node_list;
node* curr = u;
node_list.push_back(u);
//Traverse upward.
while (true) {
curr = curr->parent();
if (curr->type() == AE_VIRTUAL_ROOT) {
up = curr->parent();
//case 1: We are in a newly created c-node.
//It has only one AE, and the two neighbor-pointer point to the same one.
if (up->neighbor(0) == up->neighbor(1)) {
down = up->neighbor(0);
up->set_neighbor(down, node_list[node_list.size()-1]);
down->set_neighbor(up, node_list[0]);
curr->remove_child(node_list[node_list.size()-1]);
//There's no other child, just delete the AE.
if (curr->child_num() == 0) {
up->set_AE(0, 0);
up->set_AE(1, 0);
}
}
//case 2: General case.
else {
if (up->neighbor(0)->post_order_index() == curr->get_1st_label()) down = up->neighbor(0);
else down = up->neighbor(1);
up->set_neighbor(up->get_next(down), node_list[node_list.size()-1]);
down->set_neighbor(down->get_next(up), node_list[0]);
curr->remove_child(node_list[node_list.size()-1]);
eliminate_AE(up, down);
}
break;
}
node_list.push_back(curr);
}
//Set the "downward" AE of node_list[0].
new_AE_root = get_new_node(AE_VIRTUAL_ROOT);
new_AE_root->init_AE(node_list[0]);
//Eliminate the children other than the path.
for (size_t i = 1; i < node_list.size(); ++i) {
for (int j = 0; j < node_list[i]->child_num(); ++j) {
if (node_list[i]->child(j) != node_list[i-1]) eliminate(node_list[i]->child(j));
}
}
//Set to the boundary path.
if (node_list.size() == 1) node_list[0]->set_to_boundary_path(up, down);
else {
node_list[0]->set_to_boundary_path(down, node_list[1]);
node_list[node_list.size()-1]->set_to_boundary_path(up, node_list[node_list.size()-2]);
for (size_t i = 1; i < node_list.size()-1; ++i) {
node_list[i]->set_to_boundary_path(node_list[i-1], node_list[i+1]);
}
}
//Set the next of up and down.
up_next = up->get_next(node_list[node_list.size()-1]);
down_next = down->get_next(node_list[0]);
//Unfold the c-nodes in the node_list.
for (size_t i = 0; i < node_list.size(); ++i) {
if (node_list[i]->type() == C_NODE) c_node_extension(node_list[i]);
}
//Return the new boundary.
return pair<pair<node*, node*>, pair<node*, node*> > (pair<node*, node*>(up, up->get_next(up_next)), pair<node*, node*>(down, down->get_next(down_next)));
}
//The trim's sub-function.
//The input c-node does not contain any children nor parent, but it has two neighbors, which is originally c-node's parent and one child.
//If c-node's size equals 2, then we don't need to unfold it.
//Otherwise, it must has size equals 3.
//And then we find that redundent essential node, and remove the nodes that need not remains.
//Merge the remain part to the higher hierachy.
void
maximal_planar_subgraph_finder::c_node_extension(node* c_node) {
//size == 2
if (c_node->c_node_size() == 2) return;
//size == 3
node* sentinel = 0;
for (int i = 0; i < c_node->c_node_size(); ++i) {
if (!node::is_same(c_node->essential(i), c_node->neighbor(0)) && !node::is_same(c_node->essential(i), c_node->neighbor(1))) {
sentinel = c_node->essential(i);
break;
}
}
eliminate(sentinel);
//The two other essential nodes and their subsequent neighbor.
pair<node*, node*> sentinel_0;
pair<node*, node*> sentinel_1;
node* n0, * n0_prev = sentinel;
node* n1, * n1_prev = sentinel;
node* temp = 0;
n0 = sentinel->neighbor(0);
n1 = sentinel->neighbor(1);
while (true) {//Toward the direction of n0.
if (n0->is_sentinel()) {//If we meet a essential node, stop, don't remove it.
sentinel_0 = pair<node*, node*> (n0, n0->get_next(n0_prev));
break;
}
eliminate(n0);
temp = n0;
n0 = n0->get_next(n0_prev);
n0_prev = temp;
}
while (true) {//Toward the direction of n0.
if (n1->is_sentinel()) {//If we meet a essential node, stop, don't remove it.
sentinel_1 = pair<node*, node*> (n1, n1->get_next(n1_prev));
break;
}
eliminate(n1);
temp = n1;
n1 = n1->get_next(n1_prev);
n1_prev = temp;
}
//Remember to remove the AE toward two essential nodes that is in the delete region.
eliminate_AE(sentinel_0.first, sentinel_0.first->get_next(sentinel_0.second));
eliminate_AE(sentinel_1.first, sentinel_1.first->get_next(sentinel_1.second));
//Reset the neighborhood of two essential nodes.
sentinel_0.first->set_neighbor(sentinel_1.first, sentinel_0.second);
sentinel_1.first->set_neighbor(sentinel_0.first, sentinel_1.second);
//Merge to upper boundary cycle.
merge(pair<pair<node*, node*>, pair<node*, node*> >(sentinel_0, sentinel_1), c_node);
}
//u is a normal p-node.
//We'll do the work of elimination, and renewing of children-list.
void
maximal_planar_subgraph_finder::recursively_shaving(node* u) {
node* parent_node = 0;
node* node_x = 0;
pair<node*, node*> new_two_child;
vector<node*> new_child_list;
//p-node
if (u->type() == P_NODE) {
for (int i = 0; i < u->child_num(); ++i) recursively_shaving(u->child(i));
}
//c-node
else {
//We don't need to shave if u has only one child.
if (u->child_num() == 1) {
recursively_shaving(u->child(0));
return;
}
//More than one child.
parent_node = u->parent();
//Find node_x, and shave it.
for (int i = 0; i < u->c_node_size(); ++i) {
if (node::is_same(u->essential(i), parent_node)) {
node_x = u->essential(i);
new_two_child = shave(node_x);
break;
}
}
//Reset children-list and essential node.
for (int i = 0; i < u->child_num(); ++i) {
if (node::is_same(u->child(i), new_two_child.first) || node::is_same(u->child(i), new_two_child.second)) new_child_list.push_back(u->child(i));
else eliminate(u->child(i));
}
u->clear_children();
u->clear_essential();
u->add_essential(node_x);
u->add_essential(new_two_child.first);
u->add_essential(new_two_child.second);
u->add_child(new_child_list[0]);
u->add_child(new_child_list[1]);
for (int i = 0; i < u->child_num(); ++i) recursively_shaving(u->child(i));
}
}
//In this function, we only deal with inner part of c-node.
//x,y,z are essential nodes, let y,z be x's nearest essential nodes in w's boundary cycle.
//Anything outside [x,y], and[x,z] will be eliminated.
//Definition of y_prev, z_prev: ..., y, y_prev, ..., x, ..., z_prev, z, ...
//Return pair = (y,z). Note: What we return is the replica-node in the inner part of c-node.
//The work of deleting children will be done by recursively_shaving().
pair<node*, node*>
maximal_planar_subgraph_finder::shave(node* x) {
//c-node.
node* c_node = x->get_c_node();
//No need to shave if child_num == 1.
if (c_node->child_num() == 1) return pair<node*, node*>((node*)0, (node*)0);
//sentinel_1 = (y, y_prev). Note: At this time, c-node must has type equals ARTIFICIAL_EDGE, so no problem here.
pair<node*, node*> sentinel_1 = parallel_search_sentinel(x, c_node);
//sentinel_2 = (z, z_prev). Same as above.
pair<node*, node*> sentinel_2 = count_sentinel_elimination(sentinel_1, c_node->child_num());
return pair<node*, node*>(sentinel_1.first, sentinel_2.first);
}
//Use parallel_search to find essential nodes. Return (essential nodes that we find, its prev).
//x is not in the searching region.
//If the c-node found is top-tier, then set all the nodes during searching a pointer to c-node, set c to be that c-node, and return pair be all null.
pair<node*, node*>
maximal_planar_subgraph_finder::parallel_search_sentinel(node* x, node* &c) {
node* n0, * n0_prev = x;
node* n1, * n1_prev = x;
n0 = x->neighbor(0);
n1 = x->neighbor(1);
return parallel_search_sentinel(n0, n0_prev, n1, n1_prev, c);
}
//Another version of parallel search: n0, n0_prev, ..., n1_prev, n1
//searching region = (...n0] [n1...). Find the nearest essential node.
//return (essential nodes that we find, its prev).
pair<node*, node*>
maximal_planar_subgraph_finder::parallel_search_sentinel(node* n0, node* n0_prev, node* n1, node* n1_prev, node* & c) {
node* temp = 0;
vector<node*> traversed;
while (true) {
//If c-node is top-tier.
//note: If c points to a c-node traversed in some previous iteration, then it must not be top-tier, so it'll not pass the if-condition.
if (n0->get_c_node() != 0 && n0->get_c_node()->get_2nd_label() == NOT_VISITED) {
c = n0->get_c_node();
break;
}
if (n1->get_c_node() != 0 && n1->get_c_node()->get_2nd_label() == NOT_VISITED) {
c = n1->get_c_node();
break;
}
//If an essential-node found.
if (n0->is_sentinel()) return pair<node*, node*>(n0, n0_prev);
if (n1->is_sentinel()) return pair<node*, node*>(n1, n1_prev);
//Just a normal node..
traversed.push_back(n0);
traversed.push_back(n1);
temp = n0;
n0 = n0->get_next(n0_prev);
n0_prev = temp;
temp = n1;
n1 = n1->get_next(n1_prev);
n1_prev = temp;
}
//If the c-node found is top-tier, then assign all the traversed node a pointer to c-node.
for (size_t i = 0; i < traversed.size(); ++i) traversed[i]->set_c_node(c);
return pair<node*, node*>((node*)0, (node*)0);
}
// sentinel_1= (y, y_prev)
// return pair = (z, z_prev)
// ..., y_prev, y,[ ...(contains num_sentinel-2 essential nodes)...], z, z_prev, ... : eliminate the [...] part.
// Which means, num_sentinel = Number of essential nodes in the region [y, z].
// Note: y, z(Of course, and their prev,) will not be eliminated.
// Note: All the node that correspond to the same one as deleted node in higher hierachy will not be affected.
// The boundary cycle of c-node will be re-connected, AE be properly handled.
// Do nothing outside the c-node.
pair<node*, node*> maximal_planar_subgraph_finder::count_sentinel_elimination(pair<node*, node*> sentinel_1, int num_sentinel) {
pair<node*, node*> sentinel_2; //(z, z_prev)
int count = 1;//Count the essential nodes traversed.
node* n0 = sentinel_1.first->get_next(sentinel_1.second), * n0_prev = sentinel_1.first;//Going one step further.
node* temp = 0;
while (true) {
if (n0->is_sentinel()) {
++count;//counter
if (count == num_sentinel) {//We have reached y. Note: We will not eleminate y.
sentinel_2.first = n0;
sentinel_2.second = n0->get_next(n0_prev);
break;
}
}
eliminate(n0);
temp = n0;
n0 = n0->get_next(n0_prev);
n0_prev = temp;
}
//Remember to eliminate AE toward two essential nodes that is in the deleted region.
eliminate_AE(sentinel_2.first, sentinel_2.first->get_next(sentinel_2.second));
eliminate_AE(sentinel_1.first, sentinel_1.first->get_next(sentinel_1.second));
//Reset neighborhood of two essential nodes.
sentinel_2.first->set_neighbor(sentinel_1.first, sentinel_2.second);
sentinel_1.first->set_neighbor(sentinel_2.first, sentinel_1.second);
return sentinel_2;
}
//Used when u has label equals <i, 0>, i<j, where j is current iteration.
//Create a c-node with u being first essential node, and i being head. Return it.
//We'll done the parent-linke of (u -> c-node -> node_i).
//We don't create child-link here.
//Default label of newly contructed c-node is (INT_MAX, NOT_VISITED).
node*
maximal_planar_subgraph_finder::construct(node* u) {
//Basic works.
// int i_label = u->get_1st_label(); // unused
node* node_i = _post_order_list[u->get_1st_label()];
parenting_labeling_shaving(u, node_i);
//Get some new nodes.
node* i_sentinel = get_new_node(REPLICA_NODE);
node* u_sentinel = get_new_node(REPLICA_NODE);
node* new_c_node = get_new_node(C_NODE);
node* new_AE_root = get_new_node(AE_VIRTUAL_ROOT);
//Setting of replica-nodes.
i_sentinel->init_replica(node_i, new_c_node);
u_sentinel->init_replica(u, new_c_node);
for (int i = 0; i < u->child_num(); ++i) {
u_sentinel->add_child(u->child(i));
}
new_AE_root->init_AE(u_sentinel);
//Neighborhood setting of replica-nodes in c-node.
i_sentinel->set_to_boundary_path(u_sentinel, u_sentinel);
u_sentinel->set_to_boundary_path(i_sentinel, i_sentinel);
//Default label of c-node.
new_c_node->set_1st_label(INT_MAX);
new_c_node->set_2nd_label(NOT_VISITED);
//Set essential node of c-node.
new_c_node->add_essential(i_sentinel);
new_c_node->add_essential(u_sentinel);
//Parenting
new_c_node->set_parent(node_i);
u->set_parent(new_c_node);
//Clear children-list of u_node. (which has benn transfered to AE inside c-node.)
u->clear_children();
return new_c_node;
}
//The case when the first explored node is c-node (The input parameter c).
//The p-node that trigger c(The input parameter p), has p->c parent-link already, and p is essential(not essential before triggered).
//But we don't have c->p child-link yet.
//We are not going to establish that child-link in this function. (Will be done in BET's main loop.)
//Set c to be DELETED.
node*
maximal_planar_subgraph_finder::construct(node* c, node* p) {
//Basic works.
// int i_label = c->get_1st_label(); // unused var
node* node_i = _post_order_list[c->get_1st_label()];
parenting_labeling_shaving(p, node_i);
//note: Now, c must have exactly two children left, and c has a parent-link to p, p has achild link to c, too.
//Remember to handle them later.
//Get some new nodes.
node* i_sentinel = get_new_node(REPLICA_NODE);
node* new_c_node = get_new_node(C_NODE);
i_sentinel->init_replica(node_i, new_c_node);
//Strategy: Build thisboundary cycle first: (i, child(0), c, child(1), i).
//And then find the two replica-node corresponding to the two children in c, and merge.
node* ch0 = c->child(0);
node* ch1 = c->child(1);
node* AE_root_0 = get_new_node(AE_VIRTUAL_ROOT);
node* AE_root_1 = get_new_node(AE_VIRTUAL_ROOT);
AE_root_0->init_AE(ch0);
AE_root_1->init_AE(ch1);
i_sentinel->set_to_boundary_path(ch0, ch1);
ch0->set_to_boundary_path(i_sentinel, c);
ch1->set_to_boundary_path(i_sentinel, c);
c->set_to_boundary_path(ch0, ch1);
//find the boundary in c, merge!
node* sent_0;
node* sent_1;
node* sent_p;
for (int i = 0; i < c->c_node_size(); ++i) {
if (node::is_same(c->essential(i), ch0)) sent_0 = c->essential(i);
else if (node::is_same(c->essential(i), ch1)) sent_1 = c->essential(i);
else if (node::is_same(c->essential(i), p)) sent_p = c->essential(i);
}
merge(pair<pair<node*, node*>, pair<node*, node*> > (pair<node*, node*>(sent_0, sent_0->get_next(sent_1)), pair<node*, node*>(sent_1, sent_1->get_next(sent_0))), c);
//Set essential-node of c-node.
new_c_node->add_essential(i_sentinel);
new_c_node->add_essential(sent_p);
//Default label of c-node.
new_c_node->set_1st_label(INT_MAX);
new_c_node->set_2nd_label(NOT_VISITED);
//Parenting.
new_c_node->set_parent(node_i);
//p-node, p_sent.
sent_p->set_c_node(new_c_node);
p->clear_children();
p->set_parent(new_c_node);
//Delete c-node
c->set_2nd_label(DELETED);
return new_c_node;
}
//Some basic works in constructing c-node.
//u is the first explored node in the newly constructed c-node.
//In the case of newly constructed c-node itself is c-node, u will be the p-node that trigger the c-node.
//And in this case, p->c parent-link has been established, but c->p child-link not.
void
maximal_planar_subgraph_finder::parenting_labeling_shaving(node* u, node* node_i) {
//reverse parent-children relation in [u, node_i] as following.
//(u-> ... ->y->i) -> (u<- ... <-y , i).
vector<node*> u_i_path;
u_i_path.push_back(u);
while (true) {
u_i_path.push_back(u_i_path[u_i_path.size()-1]->parent());
if (u_i_path[u_i_path.size()-1] == node_i) break;
}
for (size_t i = 0; i < u_i_path.size()-2; ++i) {
u_i_path[i]->add_child(u_i_path[i+1]);
u_i_path[i+1]->set_parent(u_i_path[i]);
}
for (size_t i = 0; i < u_i_path.size()-2; ++i) {
for (int j = 0; j < u_i_path[i+1]->child_num(); ++j) {
if (u_i_path[i+1]->child(j) == u_i_path[i]) {
u_i_path[i+1]->remove_child(j);
}
}
}
u_i_path[0]->set_parent(0);
//BFS-traversal, all labeled to <i,1>, and then shave the c-node.
u->recursively_labeling();
recursively_shaving(u);
}

186
deferred_planarity_test/src/mps_test.cpp
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@ -1,186 +0,0 @@
//-----------------------------------------------------------------------------------
// Implementation of a MPS algorithm via PC-tree.
//-----------------------------------------------------------------------------------
#include <chrono>
#include "mps.h"
#include <ogdf/fileformats/GraphIO.h>
// #define DEBUG
// #define DEBUG_2
// #define TIME
//-----------------------------------------------------------------------------------
// Finding MPS
//-----------------------------------------------------------------------------------
// programs to call from main:
// read input file of gml format
ogdf::Graph read_from_gml(string input_file) {
ogdf::Graph G;
// utilize OGDF readGML
if (!ogdf::GraphIO::read(G, input_file, ogdf::GraphIO::readGML)) {
std::cerr << "Could not read " << input_file << ".gml" << std::endl;
}
return G;
}
int find_mps(const ogdf::Graph &G) {
maximal_planar_subgraph_finder m;
return m.find_mps(G);
}
int compute_removed_edge_size(const ogdf::Graph &G, vector<int> post_order) {
maximal_planar_subgraph_finder m;
return m.compute_removed_edge_size(G, post_order);
}
vector<int> generate_post_order(const ogdf::Graph &G) {
maximal_planar_subgraph_finder m;
return m.generate_post_order(G);
}
vector<int> generate_mutated_post_order(const ogdf::Graph &G, vector<int> post_order, int mutate_point) {
maximal_planar_subgraph_finder m;
return m.generate_mutated_post_order(G, post_order, mutate_point);
}
vector<int> generate_guided_post_order(const ogdf::Graph &G, vector<int> post_order) {
maximal_planar_subgraph_finder m;
return m.generate_guided_post_order(G, post_order);
}
void compute_mps(const ogdf::Graph &G, int mutate_point, vector<int> &post_order, int &return_edge_size) {
maximal_planar_subgraph_finder m;
m.compute_mps(G, mutate_point, post_order, return_edge_size);
}
// ---------
int maximal_planar_subgraph_finder::find_mps(const ogdf::Graph &G) {
init_from_graph(G);
postOrderTraversal();
#ifdef DEBUG
print_post_order();
#endif
sort_adj_list();
determine_edges();
back_edge_traversal();
return output_removed_edge_size();
}
vector<int> maximal_planar_subgraph_finder::generate_post_order(const ogdf::Graph &G) {
init_from_graph(G);
postOrderTraversal();
#ifdef DEBUG
std::cout << "standard post order traversal" << std::endl;
print_post_order();
#endif
return return_post_order();
}
// result of this will be used as input to "compute_removed_edge_size"
vector<int> maximal_planar_subgraph_finder::generate_mutated_post_order(const ogdf::Graph &G, const vector<int> &post_order, int mutate_point) {
init_from_graph(G);
mutatedPostOrderTraversal(post_order, mutate_point);
#ifdef DEBUG
std::cout << "mutated post order traversal" << std::endl;
print_post_order();
#endif
return return_post_order();
}
// result of this will be used as input to "compute_removed_edge_size"
vector<int> maximal_planar_subgraph_finder::generate_guided_post_order(const ogdf::Graph &G, const vector<int> &post_order) {
init_from_graph(G);
guidedPostOrderTraversal(post_order);
// #ifdef DEBUG
// std::cout << "guided post order traversal" << std::endl;
// print_post_order();
// #endif
return return_post_order();
}
int maximal_planar_subgraph_finder::compute_removed_edge_size(const ogdf::Graph &G, vector<int> post_order) {
// read_from_gml
init_from_graph(G);
// guidedPostOrderTraversal
guidedPostOrderTraversal(post_order);
sort_adj_list();
determine_edges();
back_edge_traversal();
return output_removed_edge_size();
}
void maximal_planar_subgraph_finder::reset_state() {
_post_order_list.clear();
}
void maximal_planar_subgraph_finder::compute_mps(const ogdf::Graph &G, int mutate_point, vector<int> &post_order, int &return_edge_size) {
init_from_graph(G);
mutatedPostOrderTraversal(post_order, mutate_point);
sort_adj_list();
determine_edges();
back_edge_traversal();
return_edge_size = output_removed_edge_size();
// now we get the canonical representation of the post order
vector<int> temp_post_order = return_post_order();
reset_state(); // clear the _post_order_list
// perform guided Post Order Traversal to flip the tree
guidedPostOrderTraversal(temp_post_order);
post_order = return_post_order();
}
//-----------------------------------------------------------------------------------
// Input, output
//-----------------------------------------------------------------------------------
void maximal_planar_subgraph_finder::init_from_graph(const ogdf::Graph &G) {
// create nodes
_node_list.reserve(G.numberOfNodes());
for (int i = 0; i < G.numberOfNodes(); ++i) {
_node_list.push_back(new node(P_NODE));
_node_list[i]->set_id(i);
}
// create edges
for (ogdf::edge e : G.edges) {
ogdf::node source = e->source();
ogdf::node target = e->target();
_node_list[source->index()]->add_adj(_node_list[target->index()]);
_node_list[target->index()]->add_adj(_node_list[source->index()]);
}
}
// count the number of removed edges
int maximal_planar_subgraph_finder::output_removed_edge_size() {
int sum = 0;
for (size_t i = 0; i < _back_edge_list.size(); ++i) {
if (_is_back_edge_eliminate[i]) ++sum;
}
return sum;
}

388
deferred_planarity_test/src/node.cpp
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@ -1,388 +0,0 @@
//-----------------------------------------------------------------------------------
// Implementation of a MPS algorithm via PC-tree.
//-----------------------------------------------------------------------------------
#include "mps.h"
// #define DEBUG
// #define DEBUG_MUTATION
//-----------------------------------------------------------------------------------
// CONSTRUCTOR
//-----------------------------------------------------------------------------------
node::node(node_type t) {
_type = t;
_label = pair<int, label>(INT_MAX, NOT_VISITED);
_neighbor[0] = _neighbor[1] = 0;
_AE_root[0] = _AE_root[1] = 0;
_original_node = 0;
_c_node = 0;
_parent = 0;
_post_order_index = INT_MAX;
_node_id = INT_MAX;
_mark = 0;
}
//-----------------------------------------------------------------------------------
// TYPE, ID, INDEX
//-----------------------------------------------------------------------------------
node_type node::type() {return _type;}
int node::post_order_index() {return _post_order_index;}
void node::set_id(int i) {_node_id = i;}
void node::set_post_order_index(int i) {_post_order_index = i;}
//Only used when consturcting c-node
//The first node calling this function would not be labeled.
void node::recursively_labeling() {
for (size_t i = 0; i < _children.size(); ++i) {
_children[i]->_label.second = ARTIFICIAL_EDGE;
_children[i]->recursively_labeling();
}
}
int node::node_id() {return _node_id;}
//-----------------------------------------------------------------------------------
// DFS-TREE
//-----------------------------------------------------------------------------------
void node::add_adj(node* n) {_adj_list.push_back(n);}
int node::degree() {return _adj_list.size();}
node* node::adj(int i) {return _adj_list[i];}
void node::set_adj_list(vector<node*> vec) {_adj_list = vec;}
void node::DFS_visit(vector<node*> &dfsList, int &index) {
mark();
for (size_t i = 0; i < _adj_list.size(); ++i) {
if (!_adj_list[i]->is_marked()) {
_adj_list[i]->_parent = this;
_adj_list[i]->DFS_visit(dfsList, index);
}
}
set_post_order_index(index);
dfsList.push_back(this);
++index;
}
bool node::sortByOrder(const std::unordered_map<int, int>& node_id_to_pos, node* a, node* b) {
auto iter_a = node_id_to_pos.find(a->node_id());
auto iter_b = node_id_to_pos.find(b->node_id());
// second yields the position
return iter_a->second < iter_b->second;
}
void node::guided_DFS_visit(vector<node *> &dfsList,
const vector<node *> &node_list,
int &return_index,
const unordered_map<int, int> &node_id_to_pos)
{
mark();
// purpose of this block: create list of neighbors ordered in the order they appear in rev_post_order
// we want to select neighbors that match the rev_post_order at the specific traversal_index
// implementation 1: loop through all elements
// // create an unordered set to efficiently check for presence of an element
// std::unordered_set<int> neighbor_set;
// for (int i = 0; i < _adj_list.size(); ++i) {
// neighbor_set.insert(_adj_list[i]->node_id());
// }
// // when an element in rev_post_order is found in neighbor_set, we add that to neighbor_list
// // this produces a neighbor_list that follows the order by which they occur in the rev_post_order
// // it is ok if the neighbor was already visited before,
// // it would've been marked and will be subsequently ignored
// vector<node *> neighbor_list;
// for (int i = 0; i < rev_post_order.size(); ++i) {
// if (neighbor_set.find(rev_post_order[i]) != neighbor_set.end()) {
// // only add if newly encountered
// if (!node_list[rev_post_order[i]]->is_marked()) {
// neighbor_list.push_back(node_list[rev_post_order[i]]);
// }
// }
// }
// implementation 2: sort elements of _adj_list
vector<node*> neighbor_list = _adj_list;
std::sort(neighbor_list.begin(), neighbor_list.end(), [this, &node_id_to_pos](node* a, node* b) {
return sortByOrder(node_id_to_pos, a, b);
});
#ifdef DEBUG
std::cout << "current node:" << this->node_id() << std::endl;
for (int i = 0; i < neighbor_list.size(); ++i) {
std::cout << neighbor_list[i]->node_id() << "(" << neighbor_list[i]->is_marked() << ")" << ",";
}
std::cout << std::endl;
#endif
for (size_t i = 0; i < neighbor_list.size(); ++i) {
if (!neighbor_list[i]->is_marked()) {
neighbor_list[i]->_parent = this;
neighbor_list[i]->guided_DFS_visit(dfsList, node_list, return_index, node_id_to_pos);
}
}
set_post_order_index(return_index);
dfsList.push_back(this);
++return_index;
}
void node::mutated_DFS_visit(vector<node *> &dfsList,
const vector<node *> &node_list,
int &return_index,
int &traversal_index,
const unordered_map<int, int> &node_id_to_pos,
int mutate_point,
mt19937 rng)
{
// mark current node
mark();
// purpose of this block: create list of neighbors ordered in the order they appear in rev_post_order
// we want to select neighbors that match the rev_post_order at the specific traversal_index
// // implementation 1: naively check by running through all elements of rev_post_order
// // create an unordered set to efficiently check for presence of an element
// std::unordered_set<int> neighbor_set;
// for (size_t i = 0; i < _adj_list.size(); ++i) {
// neighbor_set.insert(_adj_list[i]->node_id());
// }
// // when an element in rev_post_order is found in neighbor_set, we add that to neighbor_list
// // this produces a neighbor_list that follows the order by which they occur in the rev_post_order
// // it is ok if the neighbor was already visited before,
// // it would've been marked and will be subsequently ignored
// vector<node *> neighbor_list;
// for (size_t i = 0; i < rev_post_order.size(); ++i) {
// if (neighbor_set.find(rev_post_order[i]) != neighbor_set.end()) {
// neighbor_list.push_back(node_list[rev_post_order[i]]);
// }
// }
vector<node*> neighbor_list = _adj_list;
// if the current index matches the mutate_point, then we know this is the cycle to mutate
if (traversal_index == mutate_point) {
// we shuffle the neighbor list
std::shuffle(neighbor_list.begin(), neighbor_list.end(), rng);
// otherwise just sort based on the order set by node_id_to_pos, which is
// set by the reversed post_order
} else {
std::sort(neighbor_list.begin(), neighbor_list.end(), [this, &node_id_to_pos](node *a, node *b)
{ return sortByOrder(node_id_to_pos, a, b); });
}
#ifdef DEBUG_MUTATION
std::cout << "current node:" << this->node_id() << std::endl;
for (size_t i = 0; i < neighbor_list.size(); ++i) {
std::cout << neighbor_list[i]->node_id() << "(" << neighbor_list[i]->is_marked() << ")" << ",";
}
std::cout << std::endl;
#endif
// increment traversal index after checking
// next node will receive incremented index
traversal_index++;
for (size_t i = 0; i < neighbor_list.size(); ++i)
{
if (!neighbor_list[i]->is_marked())
{
neighbor_list[i]->_parent = this;
neighbor_list[i]->mutated_DFS_visit(dfsList, node_list, return_index, traversal_index, node_id_to_pos, mutate_point, rng);
}
}
set_post_order_index(return_index);
dfsList.push_back(this);
++return_index;
}
//-----------------------------------------------------------------------------------
// PARENT-CHILDREN
//-----------------------------------------------------------------------------------
int node::child_num() {return _children.size();}
node* node::child(int i) {return _children[i];}
node* node::parent() {return _parent;}
void node::clear_children() {
_children.clear();
}
void node::remove_child(int i) {
_children[i] = _children[_children.size()-1];
_children.resize(_children.size()-1);
}
void node::remove_child(node* n) {
for (size_t i = 0; i < _children.size(); ++i) {
if (_children[i] == n) {
_children[i] = _children[_children.size()-1];
_children.resize(_children.size()-1);
}
}
}
void node::add_child(node* n) {
_children.push_back(n);
}
vector<node*>* node::get_children_list() {
vector<node*>* ptr = new vector<node*>(_children);
return ptr;
}
void node::set_parent(node* n) {
_parent= n;
}
//-----------------------------------------------------------------------------------
// BOUNDARY_PATH
//-----------------------------------------------------------------------------------
void node::set_to_boundary_path(node* n0, node* n1) {
_parent = 0;
_children.clear();
_neighbor[0] = n0;
_neighbor[1] = n1;
set_2nd_label(BOUNDARY_PATH);
}
node* node::get_next(node* prev) {
if (_neighbor[0] != prev) return _neighbor[0];
else return _neighbor[1];
}
node* node::neighbor(int i) {return _neighbor[i];}
void node::set_neighbor(int i, node* n) {_neighbor[i] = n;}
void node::set_neighbor(node* u, node* v) {
_neighbor[0] = u;
_neighbor[1] = v;
}
//-----------------------------------------------------------------------------------
// ARTIFICIAL EDGE
//-----------------------------------------------------------------------------------
node* node::AE(int i) {return _AE_root[i];}
void node::set_AE(int i, node* j) {
_AE_root[i] = j;
if (j != 0) j->set_parent(this);
}
void node::add_AE(node* j) {
if (j == 0) return;
if (_AE_root[0] == 0) set_AE(0, j);
else if (_AE_root[1] == 0) set_AE(1, j);
}
//Inherit u's artificial edge.
void node::inherit_AE(node* u) {
if (u->_AE_root[0] != 0) add_AE(u->_AE_root[0]);
if (u->_AE_root[1] != 0) add_AE(u->_AE_root[1]);
u->_AE_root[0] = u->_AE_root[1] = 0;
}
//Set itself to be an AE-root-node in u.
//Inherite u's chilren-list.
//Do nothing if u does not have any children.
void node::init_AE(node* u) {
if (u->child_num() == 0) return;
_children = u->_children;
u->clear_children();
for (size_t i = 0; i < _children.size(); ++i) {
_children[i]->set_parent(this);
}
set_parent(u);
set_1st_label(_children[0]->get_1st_label());
set_2nd_label(ARTIFICIAL_EDGE);
u->add_AE(this);
}
//-----------------------------------------------------------------------------------
// REPLICA
//-----------------------------------------------------------------------------------
node* node::original_node() {return _original_node;}
node* node::get_c_node() {return _c_node;}
void node::set_c_node(node* c) {_c_node = c;}
bool node::is_sentinel() {return type() == REPLICA_NODE;}
//Check if n1 and n2 correspond to the same node
bool node::is_same(node* n1, node* n2) {
node* s1 = (n1->type() == REPLICA_NODE)? n1->original_node() : n1;
node* s2 = (n2->type() == REPLICA_NODE)? n2->original_node() : n2;
return s1 == s2;
}
//Set itself to be a replica-node of u in c.
//Only inherit some basic setting, not including info about neighborhood.
void node::init_replica(node* u, node* c) {
set_post_order_index(u->post_order_index());
set_2nd_label(BOUNDARY_PATH);
_original_node = (u->type() == REPLICA_NODE)? u->original_node() : u;
_c_node = c;
}
//-----------------------------------------------------------------------------------
// LABELING
//-----------------------------------------------------------------------------------
void node::set_1st_label(int i) {_label.first = i;}
void node::set_2nd_label(label i) {_label.second = i;}
int node::get_1st_label() {return _label.first;}
label node::get_2nd_label() {return _label.second;}
//-----------------------------------------------------------------------------------
// C-NODE
//-----------------------------------------------------------------------------------
node* node::get_a_list_node() {
return _essential_list[0];
}
int node::c_node_size() {
return _essential_list.size();
}
node* node::essential(int i) {
return _essential_list[i];
}
void node::clear_essential() {_essential_list.clear();}
void node::add_essential(node* u) {_essential_list.push_back(u);}
//-----------------------------------------------------------------------------------
// MARK
//-----------------------------------------------------------------------------------
void node::mark() {_mark = _ref_mark;}
void node::init_mark() {++_ref_mark;}
void node::un_mark() {_mark = 0;}
bool node::is_marked() {return _mark == _ref_mark;}
int node::_ref_mark = 1;