Cod sursa(job #2572106)

Utilizator YetoAdrian Tonica Yeto Data 5 martie 2020 11:42:37
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <fstream>
#include <vector>
#include <queue>
#define dim 50001
using namespace std;
int n, m, i, j, a, b, c, x, d[dim], nr[dim], viz[dim];
vector < pair <int, int> > g[dim];
queue <int> q;
ifstream fin ("bellmanford.in");
ofstream fout ("bellmanford.out");

int main () {
    fin>>n>>m;
    for (i=1;i<=m;i++) {
        fin>>a>>b>>c;
        g[a].push_back({b, c});
    }

    for (i=2;i<=n;i++)
        d[i]=2000000000;
    viz[1]=nr[1]=1;
    q.push(1);
    while (!q.empty()) {
        int x=q.front();
        q.pop();
        viz[x]=0;
        for (i=0;i<g[x].size();i++) {
            int vec=g[x][i].first;
            int cost=g[x][i].second;
            if (d[vec]>d[x]+cost) {
                d[vec]=d[x]+cost;
                nr[vec]++;
                if (nr[vec]==n) {
                    fout<<"Ciclu negativ!";
                    return 0;
                }
                if (viz[vec]==0) {
                    viz[vec]=1;
                    q.push(vec);
                }
            }
        }
    }
    for (i=2;i<=n;i++)
        fout<<d[i]<<" ";
    return 0;
}