Cod sursa(job #2197018)

Utilizator catalina200029Olteanu Catalina catalina200029 Data 20 aprilie 2018 21:40:43
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.2 kb
/*
Bellman-Ford
https://www.infoarena.ro/problema/bellmanford
100 puncte
*/
#include <bits/stdc++.h>

using namespace std;

ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

vector<pair<int,int>> v[50005];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> h;

int n,m,d[50005],x[50005];

int main() {
    int a,b,c,nod,i;
    f>>n>>m;
    for (i=1;i<=m;i++) {
        f>>a>>b>>c;
        v[a].push_back(make_pair(c,b));
    }
    for (i=2;i<=n;i++)
        d[i]=200000000;
    h.push(make_pair(0,1));
    d[1]=0;
    while (!h.empty()){
        nod=h.top().second;
        h.pop();
        for (i=0;i<v[nod].size();i++)
            if(d[nod]+v[nod][i].first<d[v[nod][i].second]) {
                x[v[nod][i].second]++;
                d[v[nod][i].second]=d[nod]+v[nod][i].first;
                h.push(make_pair(d[v[nod][i].second],v[nod][i].second));
                if (x[v[nod][i].second]==n) {
                    g<<"Ciclu negativ!";
                    //exit(0);
                    return 0;
                }
            }
    }
    for (i=2;i<=n;i++)
        if (d[i]==200000000) g<<"0 ";
        else g<<d[i]<<' ';
    return 0;
}