Submission #958988

#	Time	Username	Problem	Language	Result	Execution time	Memory
958988		Cyber_Wolf	Pipes (CEOI15_pipes)	C++17	30 / 100	1297 ms	65536 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

#define lg int
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

const lg N = 1e5+5;

vector<lg> adj[N];
lg n,m, low[N], tin[N], tmp, id;
set<array<lg, 2>> se;

void dfs(lg src, lg par = -1)
{
	tin[src] = low[src] = ++tmp;
	for(auto it : adj[src])
	{
		if(it == par)
		{
			continue;
		}
		if(tin[it])
		{
			if(low[it] > tin[src])
			{
				if(se.find({it, src}) != se.end())	se.erase({it, src});
			}
			low[src] = min(low[src], tin[it]);
			continue;
		}
		dfs(it, src);
		low[src] = min(low[src], low[it]);
		if(low[it] > tin[src])
		{
			se.insert({it, src});
		}
	}
	// cout << src << ' ' << low[src] << '\n';
}

int main()
{
	fastio;
	cin >> n >> m;
	for(int i = 0; i < m; i++)
	{
		lg u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	for(int i = 1; i <= n; i++)
	{
		if(!tin[i])	dfs(i);
	}
	for(auto [a, b] : se)	cout << a << ' ' << b << '\n';

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 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