Submission #1755502

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Source Code Expand

#include<bits/stdc++.h>
#define vi vector<int>
#define vvi vector<vector<int> >
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
using ll = long long;
using ld =long double;
//#define int ll
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<n;i++)
#define all(in) in.begin(), in.end()
template<class T, class S> void cmin(T &a, const S &b) { if (a > b)a = b; }
template<class T, class S> void cmax(T &a, const S &b) { if (a < b)a = b; }
#define MAX 9999999
using namespace std;
typedef pair<int, int> pii;
typedef pair<int,pii> piii;
#define mp make_pair
signed main(){
    int n,m; cin>>n>>m;
    vector<piii>edge;
    rep(i,m){
        int to,from,cost;
        cin>>to>>from>>cost;
        edge.push_back(mp(--to,mp(--from,cost)));
    }
    vector<int>d(n,INF);
    d[0]=0;
    rep(v,2*n){
        bool update=false;
        rep(j,edge.size()){
            int from=edge[j].first;
            int to=edge[j].second.first;
            int cost=edge[j].second.second;
            if(d[from]==INF)continue;
            if(d[to]>d[from]+cost){
                update=true;
                d[to]=d[from]+cost;
            }
        }
        if(update&&v>2*n-1)return puts("inf")*0;
    }
    cout<<d[n-1]<<endl;
}

Submission Info

Judge Result