Cod sursa(job #869323)

Utilizator alexalghisiAlghisi Alessandro Paolo alexalghisi Data 1 februarie 2013 13:52:55
Problema Algoritmul Bellman-Ford Scor 15
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <queue>
#define DN 50005
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define un unsigned
using namespace std;

vector<pair<int,int> > list[DN];
int dist[DN];
queue<int> q;

int n,m;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

void bfs()
{
    q.push(1);
    dist[1]=0;
    while(q.size())
    {
        int nod=q.front();
        q.pop();

        for(un int i=0;i<list[nod].size();++i)
        {
            int next_nod=list[nod][i].f;
            int cost=list[nod][i].s;
            if( dist[next_nod] > dist[nod] + cost )
            {
                dist[next_nod]=dist[nod]+cost;
                q.push(next_nod);
            }
        }
    }
}

int main()
{
    f>>n>>m;
    for(;m;--m)
    {
        int x,y,c;
        f>>x>>y>>c;
        list[x].pb(mp(y,c));
    }
    memset(dist,127,sizeof(dist));
    bfs();
    if(dist[n]<0 || dist[1]<0)
    {
        g<<"Ciclu negativ!";
        return 0;
    }
    for(int i=2;i<=n;++i)
        g<<dist[i]<<" ";
    return 0;
}