Cod sursa(job #1918982)

Utilizator KronSabau Valeriu Kron Data 9 martie 2017 17:34:58
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define Nmax 50010
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int n,m,INF=1<<29;
int dist[Nmax],inQueue[Nmax],nr[Nmax];
vector <pair<int,int> > adj[Nmax];
queue <int> q;


int bellman()
{
    for(int i=1;i<=n;i++)
        dist[i]=INF;
    dist[1]=0;
    q.push(1);
    int v,w,cost;
    while(!q.empty())
    {
        v=q.front();
        q.pop();
        inQueue[v]=0;
        for(int i=0;i<adj[v].size();i++)
        {

            w=adj[v][i].second;

            cost=adj[v][i].first;
            if(dist[w]>dist[v]+cost)
            {
                dist[w]=dist[v]+cost;
                if(!inQueue[w])
                {
                    if(nr[w]>=n+2)
                        return 0;

                    inQueue[w]=1;
                    nr[w]++;
                    q.push(w);
                }


            }
        }
    }
    return 1;
}

int main()
{
    f >> n >> m;
    int x,y,c;
    for(int i=0;i<m;i++)
    {
        f >> x >> y >> c;
        adj[x].push_back(make_pair(c,y));

    }
    if(bellman())
    {
        for(int i=2;i<=n;i++)
            g << dist[i] << " ";
    } else g << "Ciclu negativ!\n";
    return 0;
}