#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define maxn 300005
int N, K, good = 0, t = 1, low[maxn];
vector<int> adj[maxn], rev[maxn];
void init(int n, int k){
N = n, K = k;
for(int i = 0; i < k - 1; ++i) adj[i].pb(i + 1), rev[i + 1].pb(i);
for(int i = 0; i < n; ++i) low[i] = i;
}
int add_teleporter(int u, int v){
if(u == v){
if(u < K) return 1;
else return 0;
}
adj[u].pb(v);
rev[v].pb(u);
low[u] = min(low[v], low[u]);
queue<int> bfs; bfs.push(u);
while(bfs.size()){
int u = bfs.front(); bfs.pop();
for(auto v:rev[u]){
if(low[v] > low[u]) {
low[v] = low[u];
bfs.push(v);
}
}
}
for(int i = 0; i < K; ++i){
if(low[i] < i) return 1;
}
return 0;
}
int main(){
int n, m, k; cin >> n >> m >> k;
init(n, k);
bool ok = 1;
for(int i = 0; i < m; ++i){
int u, v; cin >> u >> v;
if(add_teleporter(u, v)) {
cout << i << '\n';
ok = 0;
break;
}
}
if(ok) cout << m << '\n';
}
Compilation message
/usr/bin/ld: /tmp/ccoEGuWV.o: in function `main':
stub.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccGOvjhW.o:game.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
