Cod sursa(job #2521236)

Utilizator YetoAdrian Tonica Yeto Data 10 ianuarie 2020 16:21:53
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <fstream>
#include <vector>
#include <queue>
#define dim 50001
using namespace std;
int n, m, a, b, c, i, d[dim], nr[dim];
bool 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;
    q.push(1);
    viz[1]=nr[1]=1;
    while(!q.empty()) {
        int x=q.front();
        q.pop();
        viz[x]=0;
        for(int j=0;j<g[x].size();j++) {
            int v=g[x][j].first;
            int c=g[x][j].second;
            if(d[v]>d[x]+c) {
                d[v]=d[x]+c;
                nr[v]++;
                if(nr[v]==n) {
                    fout<<"Ciclu negativ!";
                    return 0;
                }
                if(viz[v]==0) {
                    q.push(v);
                    viz[v]=1;
                }
            }
        }
    }
    for (i=2;i<=n;i++)
        fout<<d[i]<<" ";
    return 0;
}