Cod sursa(job #933318)

Utilizator vendettaSalajan Razvan vendetta Data 29 martie 2013 20:18:18
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.4 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <set>
#include <queue>
#include <deque>

using namespace std;

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

#define nmax 50005
#define ll long long
#define inf (1<<30)

int n, m, viz[nmax], dist[nmax];
vector< pair<int,int> > gf[nmax];
bool inCoada[nmax];
queue<int> q;

void citeste(){
    f >> n >> m;
    int x, y, z;
    for(int i=1; i<=m; ++i){
        f >> x >> y >> z;
        gf[x].push_back( make_pair(y, z) );
    }
}

void rezolva(){
    for(int i=1;i <=n; ++i) dist[i] = inf;
    q.push(1); inCoada[1] = 1;
    dist[1] = 0;

    for(; q.size(); ){
        int nod = q.front(); q.pop();
        inCoada[nod] = 0;
        for(int i=0; i<gf[nod].size(); ++i){
            int vc = gf[nod][i].first;
            int cost = gf[nod][i].second;
            if (dist[vc] > dist[nod] + cost){
                dist[vc] = dist[nod] + cost;
                if (inCoada[vc] == 0){
                    if (viz[vc] > n){
                        g << "Ciclu negativ!" << "\n";
                        return;
                    }
                    ++viz[vc]; inCoada[vc] = 1; q.push(vc);
                }
            }
        }
    }
    for(int i=2; i<=n; ++i) g << dist[i] << " ";
    g << "\n";
}

int main(){
    citeste();
    rezolva();

    f.close();
    g.close();

    return 0;
}