Submission #311493

#	Time	Username	Problem	Language	Result	Execution time	Memory
311493		Kenzo_1114	Pipes (CEOI15_pipes)	C++17	0 / 100	1586 ms	65540 KiB

pipes

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 10001;

int n, m, low[MAXN], depth[MAXN];
vector<int> graph[MAXN];
map<pair<int, int> , bool> marc;

void dfs(int v, int p)
{
	depth[v] = (v == p) ? 0 : depth[p] + 1;
	low[v] = depth[v];

	bool first = false;
	for(int i = 0; i < graph[v].size(); i++)
	{
		int u = graph[v][i];
		
		if(low[u] >= 0)
		{
			if(u != p || first)	low[v] = min(low[v], depth[u]);
			if(u == p)	first = true;
			continue;	
		}

		dfs(u, v);
		low[v] = min(low[v], low[u]);

		if(low[u] > depth[v])	printf("%d %d\n", u, v);
	}
}

int main ()
{
	scanf("%d %d", &n, &m);

	for(int i = 1; i <= n; i++)	low[i] = -1;

	for(int i = 0, u, v; i < m; i++)
	{
		scanf("%d %d", &u, &v);
		if(marc[{u, v}])	continue;
		marc[{u, v}] = true;
		graph[u].push_back(v);
		graph[v].push_back(u);
	}

	for(int i = 1; i <= n; i++)	
		if(low[i] == -1) dfs(i, i);
}

/*

10 11
1 7
1 8
1 6
2 8
6 7
5 8
2 5
2 3
2 4
3 4
10 9


*/

Compilation message (stderr)

pipes.cpp: In function 'void dfs(int, int)':
pipes.cpp:15:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |  for(int i = 0; i < graph[v].size(); i++)
      |                 ~~^~~~~~~~~~~~~~~~~
pipes.cpp: In function 'int main()':
pipes.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
pipes.cpp:41:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   41 |   scanf("%d %d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10