Cod sursa(job #1370125)

Utilizator rares96cheseliRares Cheseli rares96cheseli Data 3 martie 2015 13:04:16
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1 kb
#include <algorithm>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

int N, M, x, y, c, D[50005], used[50005], inQ[50005];
vector < pair<int, int> > G[50005];
queue < int > Q;

int main()
{
    f>>N>>M;
    for (int i=1; i<=M; ++i)
    {
        f>>x>>y>>c;
        G[x].push_back(make_pair(y, c));
    }

    for (int i=1; i<=N; ++i)
        D[i]=(1<<30);
    Q.push(1); D[1]=0;
    while (Q.size())
    {
        int nod=Q.front(); Q.pop();
        ++used[nod];
        if (used[nod]==N)
        {
            g<<"Ciclu negativ\n"; return 0;
        }

        vector< pair<int, int> >::iterator it=G[nod].begin();
        for (; it!=G[nod].end(); ++it)
            if (D[nod]+it->second < D[it->first])
            {
                D[it->first]=D[nod]+it->second;
                Q.push(it->first);
            }
    }

    for (int i=2; i<=N; ++i)
        g<<D[i]<<' ';
    return 0;
}