Bug: fixed broken guided traversal. Discovered that guided traversal

rotates the dfs tree.
This commit is contained in:
Richard Wong 2024-02-22 10:52:36 +09:00
parent 54b51b002d
commit 8ca09dbf9e
Signed by: richard
GPG Key ID: 5BD36BA2E9EE33D0
5 changed files with 132 additions and 38 deletions

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@ -56,8 +56,17 @@ public:
node* adj(int i); node* adj(int i);
void set_adj_list(vector<node*> vec); void set_adj_list(vector<node*> vec);
void DFS_visit(vector<node*> &dfsList, int &index); void DFS_visit(vector<node*> &dfsList, int &index);
void guided_DFS_visit(vector<node*> &dfsList, vector<node*> &node_list, int &index, vector<int> rev_post_order); void guided_DFS_visit(vector<node *> &dfsList,
void mutated_DFS_visit(vector<node*> &dfsList, vector<node*> &node_list, int &index, vector<int> rev_post_order, int &mutate_point); vector<node *> &node_list,
int &return_index,
vector<int> rev_post_order,
int prev_node);
void mutated_DFS_visit(vector<node*> &dfsList,
vector<node*> &node_list,
int &index,
int &traversal_index,
vector<int> rev_post_order,
int mutate_point);
//PARENT-CHILDREN //PARENT-CHILDREN
void set_parent(node* n) ; void set_parent(node* n) ;
@ -150,6 +159,7 @@ public:
int compute_removed_edge_size(string input_file, vector<int> post_order); int compute_removed_edge_size(string input_file, vector<int> post_order);
vector<int> generate_post_order(string input_file); vector<int> generate_post_order(string input_file);
vector<int> generate_mutated_post_order(string input_file, vector<int> post_order); vector<int> generate_mutated_post_order(string input_file, vector<int> post_order);
vector<int> generate_guided_post_order(string input_file, vector<int> post_order);
node* get_new_node(node_type t); node* get_new_node(node_type t);
void read_from_gml(string input_file); void read_from_gml(string input_file);
int output_removed_edge_size(); int output_removed_edge_size();

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@ -21,15 +21,31 @@ int compute_removed_edge_size(string input_file, vector<int> post_order);
vector<int> generate_post_order(string input_file); vector<int> generate_post_order(string input_file);
vector<int> generate_mutated_post_order(string input_file, vector<int> post_order); vector<int> generate_mutated_post_order(string input_file, vector<int> post_order);
vector<int> generate_guided_post_order(string input_file, vector<int> post_order);
vector<int> repeated_mutation(string input_file, int k_max) { vector<int> repeated_mutation(string input_file, int k_max) {
// generate first post order
std::cout << "generate first post order" << std::endl;
vector<int> state_old = generate_post_order(input_file); vector<int> state_old = generate_post_order(input_file);
vector<int> state_new; vector<int> state_new;
int num_removed_edges; int num_removed_edges;
for (int k = 0; k < k_max; ++k) { for (int k = 0; k < k_max; ++k) {
state_new = generate_mutated_post_order(input_file, state_old); // rotate it first
num_removed_edges = compute_removed_edge_size(input_file, state_new); std::cout << "cycle:" << k << std::endl;
std::cout << "rotate the dfs tree" << std::endl;
state_new = generate_guided_post_order(input_file, state_old);
// then the next traversal will rotate it back
std::cout << "mutate the dfs tree" << std::endl;
state_new = generate_mutated_post_order(input_file, state_new);
// num_removed_edges = compute_removed_edge_size(input_file, state_new);
// first time will rotate the tree
std::cout << "rotate the dfs tree" << std::endl;
state_new = generate_guided_post_order(input_file, state_new);
// second time will rotate back the rotated tree
std::cout << "print the mutated tree again" << std::endl;
state_new = generate_guided_post_order(input_file, state_new);
std::cout << std::endl;
} }
return state_new; return state_new;
} }
@ -62,8 +78,8 @@ int main(int argc, char* argv[]) {
int k_max = std::stoi(argv[2]); int k_max = std::stoi(argv[2]);
// generate order here // generate order here
// vector<int> post_order = repeated_mutation(input_file, k_max); vector<int> post_order = repeated_mutation(input_file, k_max);
test_correctness(input_file); // test_correctness(input_file);
// // print final order and number of edges // // print final order and number of edges
// // print post_order // // print post_order

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@ -61,19 +61,21 @@ maximal_planar_subgraph_finder::guidedPostOrderTraversal(vector<int> post_order)
int end_condition = _node_list.size(); int end_condition = _node_list.size();
int start = rev_post_order[0]; int start = rev_post_order[0];
int i = start; int i = start;
int prev_node = INT_MAX;
while (true) while (true)
{ {
if (((start > 0) && (i == (start - 1))) || ((start == 0 ) && (i == end_condition - 1))) if (((start > 0) && (i == (start - 1))) || ((start == 0 ) && (i == end_condition - 1)))
{ {
if (!_node_list[i]->is_marked()) if (!_node_list[i]->is_marked())
{ {
_node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order); _node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order, prev_node);
} }
break; break;
} }
if (!_node_list[i]->is_marked()) if (!_node_list[i]->is_marked())
{ {
_node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order); _node_list[i]->guided_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order, prev_node);
} }
i = (i + 1) % end_condition; i = (i + 1) % end_condition;
} }
@ -91,6 +93,7 @@ maximal_planar_subgraph_finder::mutatedPostOrderTraversal(vector<int> post_order
rev_post_order.push_back(post_order[i]); rev_post_order.push_back(post_order[i]);
} }
int postOrderID = 0; int postOrderID = 0;
int traversal_index = 0;
// introduce random selection // introduce random selection
std::random_device rd; std::random_device rd;
@ -123,13 +126,13 @@ maximal_planar_subgraph_finder::mutatedPostOrderTraversal(vector<int> post_order
{ {
if (!_node_list[i]->is_marked()) if (!_node_list[i]->is_marked())
{ {
_node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order, mutate_point); _node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, traversal_index, rev_post_order, mutate_point);
} }
break; break;
} }
if (!_node_list[i]->is_marked()) if (!_node_list[i]->is_marked())
{ {
_node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, rev_post_order, mutate_point); _node_list[i]->mutated_DFS_visit(_post_order_list, _node_list, postOrderID, traversal_index, rev_post_order, mutate_point);
} }
i = (i + 1) % end_condition; i = (i + 1) % end_condition;
} }

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@ -33,6 +33,11 @@ vector<int> generate_mutated_post_order(string input_file, vector<int> post_orde
return m.generate_mutated_post_order(input_file, post_order); return m.generate_mutated_post_order(input_file, post_order);
} }
vector<int> generate_guided_post_order(string input_file, vector<int> post_order) {
maximal_planar_subgraph_finder m;
return m.generate_guided_post_order(input_file, post_order);
}
// --------- // ---------
@ -55,6 +60,7 @@ vector<int> maximal_planar_subgraph_finder::generate_post_order(string input_fil
postOrderTraversal(); postOrderTraversal();
#ifdef DEBUG #ifdef DEBUG
std::cout << "standard post order traversal" << std::endl;
print_post_order(); print_post_order();
#endif #endif
@ -67,6 +73,20 @@ vector<int> maximal_planar_subgraph_finder::generate_mutated_post_order(string i
mutatedPostOrderTraversal(post_order); mutatedPostOrderTraversal(post_order);
#ifdef DEBUG #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(string input_file, vector<int> post_order) {
read_from_gml(input_file);
guidedPostOrderTraversal(post_order);
#ifdef DEBUG
std::cout << "guided post order traversal" << std::endl;
print_post_order(); print_post_order();
#endif #endif
@ -74,16 +94,13 @@ vector<int> maximal_planar_subgraph_finder::generate_mutated_post_order(string i
} }
int maximal_planar_subgraph_finder::compute_removed_edge_size(string input_file, vector<int> post_order) { int maximal_planar_subgraph_finder::compute_removed_edge_size(string input_file, vector<int> post_order) {
read_from_gml(input_file); read_from_gml(input_file);
guidedPostOrderTraversal(post_order); guidedPostOrderTraversal(post_order);
// set post_order_index
for (int i = 0; i < _post_order_list.size(); ++i) {
_node_list[_post_order_list[i]->node_id()]->set_post_order_index(i);
}
#ifdef DEBUG #ifdef DEBUG
std::cout << "guided post order traversal" << std::endl;
print_post_order(); print_post_order();
#endif #endif

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@ -69,50 +69,96 @@ void node::DFS_visit(vector<node*> &dfsList, int &index) {
} }
void node::guided_DFS_visit(vector<node*> &dfsList, vector<node*> &node_list, int &index, vector<int> rev_post_order) { void node::guided_DFS_visit(vector<node *> &dfsList,
vector<node *> &node_list,
int &return_index,
vector<int> rev_post_order,
int prev_node)
{
mark(); 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
// purpose of this block: create list of neighbors // create an unordered set to efficiently check for presence of an element
vector<node *> neighbor_list; std::unordered_set<int> neighbor_set;
for (int i = 0; i < _adj_list.size(); ++i) { for (int i = 0; i < _adj_list.size(); ++i) {
// we get the neighbors via _adj_list neighbor_set.insert(_adj_list[i]->node_id());
// we get the id's of the neighbor nodes, then we use the id's to get the actual nodes via node_list
// node_list maps id to the actual node
neighbor_list.push_back(node_list[_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]]);
}
}
}
#ifdef DEBUG
std::cout << "current node:" << this->node_id() << std::endl;
std::cout << "prev node:" << prev_node << 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 (int i = 0; i < neighbor_list.size(); ++i) { for (int i = 0; i < neighbor_list.size(); ++i) {
if (!neighbor_list[i]->is_marked()) { if (!neighbor_list[i]->is_marked()) {
neighbor_list[i]->_parent = this; neighbor_list[i]->_parent = this;
neighbor_list[i]->guided_DFS_visit(dfsList, node_list, index, rev_post_order); neighbor_list[i]->guided_DFS_visit(dfsList, node_list, return_index, rev_post_order, this->node_id());
} }
} }
set_post_order_index(index); set_post_order_index(return_index);
dfsList.push_back(this); dfsList.push_back(this);
++index; ++return_index;
} }
void node::mutated_DFS_visit(vector<node*> &dfsList, vector<node*> &node_list, int &index, vector<int> rev_post_order, int &mutate_point) { void node::mutated_DFS_visit(vector<node*> &dfsList,
vector<node*> &node_list,
int &return_index,
int &traversal_index,
vector<int> rev_post_order,
int mutate_point)
{
// mark current node // mark current node
mark(); mark();
// purpose of this block: create list of neighbors // purpose of this block: create list of neighbors ordered in the order they appear in rev_post_order
vector<node *> neighbor_list; // we want to select neighbors that match the rev_post_order at the specific traversal_index
// 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) { for (int i = 0; i < _adj_list.size(); ++i) {
// we get the neighbors via _adj_list neighbor_set.insert(_adj_list[i]->node_id());
// we get the id's of the neighbor nodes, then we use the id's to get the actual nodes via node_list
// node_list maps id to the actual node
neighbor_list.push_back(node_list[_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()) {
neighbor_list.push_back(node_list[rev_post_order[i]]);
}
}
// since we increment the index before this line, the current index is "index - 1" // since we increment the index before this line, the current index is "index - 1"
// if the current index matches the mutate_point, then we know this is the cycle to mutate // if the current index matches the mutate_point, then we know this is the cycle to mutate
if (index - 1 == mutate_point) { if (traversal_index == mutate_point) {
// Create a random number generator and seed it // Create a random number generator and seed it
// std::cout << "mutated at index: " << index - 1<< "and at mutate point: " << mutate_point << std::endl; // std::cout << "mutated at index: " << index - 1<< "and at mutate point: " << mutate_point << std::endl;
std::random_device rd; std::random_device rd;
@ -121,22 +167,24 @@ void node::mutated_DFS_visit(vector<node*> &dfsList, vector<node*> &node_list, i
std::shuffle(neighbor_list.begin(), neighbor_list.end(), rng); std::shuffle(neighbor_list.begin(), neighbor_list.end(), rng);
} }
// increment traversal index after checking
// next node will receive incremented index
traversal_index++;
for (int i = 0; i < neighbor_list.size(); ++i) for (int i = 0; i < neighbor_list.size(); ++i)
{ {
if (!neighbor_list[i]->is_marked()) if (!neighbor_list[i]->is_marked())
{ {
neighbor_list[i]->_parent = this; neighbor_list[i]->_parent = this;
neighbor_list[i]->mutated_DFS_visit(dfsList, node_list, index, rev_post_order, mutate_point); neighbor_list[i]->mutated_DFS_visit(dfsList, node_list, return_index, traversal_index, rev_post_order, mutate_point);
} }
} }
set_post_order_index(index); set_post_order_index(return_index);
dfsList.push_back(this); dfsList.push_back(this);
++index; ++return_index;
} }
//----------------------------------------------------------------------------------- //-----------------------------------------------------------------------------------
// PARENT-CHILDREN // PARENT-CHILDREN
//----------------------------------------------------------------------------------- //-----------------------------------------------------------------------------------