Shared code

#include <bits/stdc++.h>
#define db(x) cout<<x<<" "
#define db1(x) cout<<x<<'\n'
#define db2(x,y) cout<<x<<" "<<y<<'\n'
#define db3(x,y,z) cout<<x<<" "<<y<<" "<<z<<'\n'
#define rep(i,n) for(int i=0;i<(n);++i)
#define repA(i,a,n) for(int i=a;i<=(n);++i)
#define repD(i,a,n) for(int i=a;i>=(n);--i)
#define pair(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define ll  long long int
#define all(a) a.begin(), a.end()
#define MAX_N 1e5
using namespace std;
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
char dir[4] = {'R', 'L', 'D', 'U'};
bool check= false;
vector<bool>visit(2501, false);

class Edge {
  public :
    int src;
    int dest;
    int weight;
};


class Graph{
  public :
  int v;
  int e;
  Edge *edge; 

  Graph (int v, int e) {
    this ->v = v;
    this ->e = e;
    edge = new Edge[e];
  }

  void addEdge (int u, int v, int w, int count) {
    edge[count].src = u;
    edge[count].dest = v;
    edge[count].weight = w;
  }

  bool BellmanFord (int src) {

    ll distance[v];
    ll parent[v];
    memset(parent, -1, sizeof(parent));
    
    ll x;

    for (int i=0; i<v; i++) {
      if (i==src) {
        distance[i] = 0;
      }
      else {
        distance[i] = LLONG_MAX;
      }
    }

    //Relaxation Code
    for (int i = 1; i<=v; i++) {

       x = -1;


      for (int j=0; j<e; j++) {

          int source = edge[j].src;
          int destnation = edge[j].dest;
          int wt = edge[j].weight;
          //visit[source] = true;

          if (distance[source]!=LLONG_MAX && distance[destnation]>distance[source] + wt) {
            visit[source] = true;
            distance[destnation] = distance[source] + wt;
            parent[destnation] = source;
            x = destnation;
          } 

      }

    }

    if(x==-1)
      return false;

    check = true;

    db1("YES");

    rep(i,v)
    x = parent[x];

    vector<ll>cycle;

    ll sex = x;

    while(1) {
      cycle.push_back(sex);
      if(sex==x && cycle.size()>1)
        break;
      sex = parent[sex];
    }

    reverse(all(cycle));

    rep(i, cycle.size()) {
      db(cycle[i]+1);
    }

     return true;

  }

 

};


void solve(){  
    
   ll n,m;
   cin>>n>>m;
   
   Graph g(n, m);
   ll src=0;
   vector<ll>source;

   rep(i, m) {
    ll u,v,w;
    cin>>u>>v>>w;
    u--;
    v--;
    g.addEdge(u,v,w,i);
    source.push_back(u);
   }

   
   rep(i,source.size())   {
    if(visit[source[i]] == false && g.BellmanFord(source[i])) {
      return;
    }
   }

   db1("NO");
   

}

 
int main(){ 
  int t=1;
//cin>>t;
  while(t--){
   solve();
  }
  return 0;
}