Submission #340938

#	Time	Username	Problem	Language	Result	Execution time	Memory
340938		pggp	Simurgh (IOI17_simurgh)	C++14	13 / 100	23 ms	6892 KiB

simurgh

#include <bits/stdc++.h>
#include "simurgh.h"

using namespace std;


int k[30000];

vector < int > E[30000];
vector < int > E_id[30000];
bool used[30000];
int parent[30000];
int parent_road[30000];
int depth[30000];

vector < int > u_back, v_back;
vector < int > id;

vector < int > tree;

void dfs(int vertex){
	//outcout << vertex << endl;
	used[vertex] = true;
	for(int i = 0; i < E[vertex].size(); i++){
		int v = E[vertex][i];
		if(!used[v]){
			parent[v] = vertex;
			parent_road[v] = E_id[vertex][i];
			tree.push_back(parent_road[v]);

			//cout << vertex << " to " << v << endl;
			depth[v] = depth[vertex] + 1;
			dfs(v);
		}
		else if (v != parent[vertex] and depth[v] < depth[vertex]){
			v_back.push_back(vertex);
			u_back.push_back(v);
			id.push_back(E_id[vertex][i]);
		}
	}
}


vector < int > find_roads(int n, vector < int > u, vector < int > v){

	int m = u.size();
	for (int i = 0; i < m; ++i)
	{
		k[i] = -1;
	}

	for (int i = 0; i < m; ++i)
	{
		E[u[i]].push_back(v[i]);
		E_id[u[i]].push_back(i);
		E[v[i]].push_back(u[i]);
		E_id[v[i]].push_back(i);
	}
	parent[0] = -1;
	dfs(0);

	int tr = count_common_roads(tree);

	// tutaj zaczyna się zabawa z cyklami
	for(int i = 0; i < v_back.size(); i++){
		vector < int > cycle;
		cycle.push_back(id[i]);
		int cur = v_back[i];
		//cout << v_back[i] << " " << u_back[i] << endl;
		while(cur != u_back[i]){
			cycle.push_back(parent_road[cur]);
			cur = parent[cur];
		}
		vector < int > an;

		int minim = 100000;
		int maxim = 0;

		int sample_k, sample_result;
		bool sampled = false;

		for(int t : cycle){
			if(t == id[i]){
				//cout << t << " - " << tr << endl;
				an.push_back(tr);
				minim = min(minim, tr);
				maxim = max(maxim, tr);
				continue;
			}
			if(k[t] != -1 and sampled){
				//cout << "OK" << endl;
				continue;
			}
			if(k[t] != -1 and !sampled){
				//cout << "t = " << t  << " k[" << t << "] = " << k[t] << endl;
				sample_k = k[t];
				sampled = true;
			}
			//cout << "t = " << t << endl;
			vector < int > to_q;
			// drzewo z cyklem bez t
			for(int e : tree){
				if(e != t){
					to_q.push_back(e);
				}
			}
			to_q.push_back(id[i]);
			int resp = count_common_roads(to_q);
			an.push_back(resp);
			//cout << t << " resp = " << resp << endl;
			minim = min(minim, resp);
			maxim = max(maxim, resp);
			if(k[t] != -1){
				sample_result = resp;
				sampled = true;
			}
		}

		if(maxim == minim and (!sampled or (sample_k == 0))){
			for(int e : cycle){
				if(k[e] == -1)	k[e] = 0;
				//cout << "e = " <<  e << " sampled = " << sampled << " sample_k = " << sample_k << endl;
			}
		}
		if(maxim == minim and sampled and sample_k == 1){
			for(int e : cycle){
				//cout << "E = " << e << endl;
				if(k[e] == -1)	k[e] = 1;
			}
		}

		for (int j = 0; j < an.size(); ++j)
		{
			if(an[j] == maxim){
				//cout << "k["  << cycle[j] << "] = " << 0 << endl;
				if(k[cycle[j]] == -1)	k[cycle[j]] = 0;
			}
			else{
				//cout << "k["  << cycle[j] << "] = " << 1 << endl;
				if(k[cycle[j]] == -1)	k[cycle[j]] = 1;
			}
		}


//		cout << endl;
	}


	vector < int > ans;
	for (int i = 0; i < m; ++i)
	{
		if(k[i] == 1 or k[i] == -1){
			ans.push_back(i);
		}
	}
	return ans;
}

Compilation message (stderr)

simurgh.cpp: In function 'void dfs(int)':
simurgh.cpp:24:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  for(int i = 0; i < E[vertex].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:65:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |  for(int i = 0; i < v_back.size(); i++){
      |                 ~~^~~~~~~~~~~~~~~
simurgh.cpp:132:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |   for (int j = 0; j < an.size(); ++j)
      |                   ~~^~~~~~~~~~~
simurgh.cpp:79:17: warning: variable 'sample_result' set but not used [-Wunused-but-set-variable]
   79 |   int sample_k, sample_result;
      |                 ^~~~~~~~~~~~~
simurgh.cpp:79:7: warning: 'sample_k' may be used uninitialized in this function [-Wmaybe-uninitialized]
   79 |   int sample_k, sample_result;
      |       ^~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 17
• Subtask 3: 0 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30