#include "islands.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
const int maxn = 2e5+10;
int n, m, tin[maxn], low[maxn], mark[maxn], can[maxn], timer;
vector<int> g[maxn], gt[maxn];
void dfsscc(int u) {
tin[u] = ++timer;
low[u] = tin[u];
for(auto v : g[u]) {
if(mark[v] != 0 && mark[v] != mark[u]) continue;
if(mark[v] != 0) {
low[v] = min(low[v],tin[u]);
}
else {
mark[v] = mark[u];
dfsscc(v);
low[u] = min(low[u],low[v]);
}
}
}
variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V) {
n = N;
m = M;
for(int i = 0; i < m; i++) {
g[U[i]].pb(V[i]);
gt[V[i]].pb(U[i]);
}
int cntm = 0;
for(int i = 0; i < m; i++) {
if(!mark[i]) {
mark[i] = ++cntm;
dfsscc(i);
}
}
for(int i = 0; i < m; i++) {
can[i] = 0;
if(low[i] < tin[i]) can[i] = 1;
}
return (can[0] == 1);
if (N == 4) {
return std::vector<int>({0, 1, 2, 4, 0, 3, 2, 1, 4, 3});
}
return false;
}
