Submission #86678

#	Time	Username	Problem	Language	Result	Execution time	Memory
86678		dimash241	Pipes (CEOI15_pipes)	C++17	10 / 100	435 ms	65536 KiB

pipes

# include <stdio.h>
# include <bits/stdc++.h>
 
#define Accepted 0
#define pb push_back
#define F first
#define S second
#define For(i,x,y)  for (int i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (int i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0)
 
using namespace std;
 
int n, m;
bitset < 70101 > g[70101];
bitset < 70101 > has[70101];
bitset < 70101 > was[70101];
vector < pair < int, int > > ans;
 
int tin[70101];
int fup[70101];
int timer;
 
inline void dfs (int v, int par) {
	tin[v] = fup[v] = ++ timer;
	for (int i = g[v]._Find_first(); i < g[v].size(); i = g[v]._Find_next(i)) {
		if (i == par) continue;
		if (tin[i]) {
			fup[v] = min(fup[v], tin[i]);
		} else {
			dfs (i, v);
			fup[v] = min(fup[v], fup[i]);
			if (tin[v] < fup[i]) {
				if(has[v][i]) continue;
				ans.pb({min(v, i), max(v, i)});
			}
		}
	}
}
 
int main () {               
    cin >> n >> m;
    For (i, 1, m) {
    	int l, r;
    	cin >> l >> r;
    	if (was[l][r]) {
    		has[l][r] = 1;
  		  	has[r][l] = 1;
  		}
    	was[l][r] = 1;
    	was[r][l] = 1;
    	g[l][r] = 1;
    	g[r][l] = 1;
    }
 
    For (i, 1, n) {
    	if (!tin[i]) {
    		dfs (i, i);
    	}
    }
 
    for (auto it : ans)
    	cout << it.F << ' ' << it.S << '\n';
    return Accepted;
}

Compilation message (stderr)

pipes.cpp: In function 'void dfs(int, int)':
pipes.cpp:26:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = g[v]._Find_first(); i < g[v].size(); i = g[v]._Find_next(i)) {
                                   ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 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