Cod sursa(job #1878459)

Utilizator andrei.sasaAndrei SaSa andrei.sasa Data 14 februarie 2017 10:33:34
Problema Algoritmul Bellman-Ford Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include <iostream>
#include <fstream>
#include <vector>
#define MAXX 2000

using namespace std;

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

vector <pair <int, int> > G[50010];

int n,m,d[50010];;

int bellman_ford(int x0)
{
    for(int i=1;i<=n;i++)
        d[i]=MAXX;
    d[x0]=0;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            {
                int l=G[j].size();
                for(int k=0;k<l;k++)
                    if(d[G[j][k].first]>d[j]+G[j][k].second) d[G[j][k].first]=d[j]+G[j][k].second;
            }
    for(int j=1;j<=n;j++)
            {
                int l=G[j].size();
                for(int k=0;k<l;k++)
                    if(d[G[j][k].first]>d[j]+G[j][k].second) return 0;
            }
    return 1;
}

int main()
{
    f>>n>>m;
    while(m--)
    {
        int a,b,c;
        f>>a>>b>>c;
        G[a].push_back(make_pair(b,c));
    }
    if(bellman_ford(1))
    for(int i=2;i<=n;i++)
        g<<d[i]<<' ';
    else g<<"Ciclu negativ!";
    return 0;
}