#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define endl "\n"
#define pii pair<ll,ll>
#define pb push_back
#define vi vector<ll>
#define pque priority_queue
#define pqueg priority_queue<ll,vector<ll>,greater<ll>>
#define que queue<ll>
#define FOR(m,i,n) for(int i=(m); i<=(n); i++)
#define FORM(m,i,n) for(int i=(m); i>=(n); i--)
ll n,m,u,v;
bool vis[200200],cycle,in[200200];
vector<ll> adj[200200],ans;
int top[200200];
void dfs(ll x) {
vis[x] = true;
in[x] = true;
for(auto i : adj[x]) {
top[i]--;
if(top[i] == 0) {
ans.pb(i);
}
if(!vis[i]) {
dfs(i);
}
else if(in[i]) {
cycle = true;
return;
}
}
in[x] = false;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
FOR(1,i,m) {
cin >> u >> v;
adj[v].pb(u);
top[u]++;
}
FOR(1,i,n) {
if(top[i] == 0) {
dfs(i);
if(cycle) {
cout << -1 << endl;
return 0;
}
}
}
for(auto i : ans) {
cout << i << " 1" << endl;
}
}
/*
5 5
3 1
2 3
4 2
5 2
5 4
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Incorrect |
2 ms |
4908 KB |
Unexpected end of file - int32 expected |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
66 ms |
12900 KB |
Integer parameter [name=d] equals to 85108, violates the range [0, 1] |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Incorrect |
2 ms |
4908 KB |
Unexpected end of file - int32 expected |
4 |
Halted |
0 ms |
0 KB |
- |