Cod sursa(job #1753581)

Utilizator AcuasPopescu Nicolae-Aurelian Acuas Data 6 septembrie 2016 18:43:38
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <fstream>
#include <vector>
#include <algorithm>
#include <climits>
#include <queue>
#define NMAX 50100
#define INF INT_MAX
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
vector<int> G[NMAX],C[NMAX];
queue<int> coada;
int n,m,d[NMAX],viz[NMAX],t[NMAX];
void citire(){
    f>>n>>m;
    int i,x,y,z;
    for(i=1;i<=m;i++){
        f>>x>>y>>z;
        G[x].push_back(y);
        C[x].push_back(z);
    }
}
void bellman_ford(){
    int i,j,k;
    d[1]=0;
    for(i=2;i<=n;i++)
        d[i]=INF;
    coada.push(1);
    viz[1]=1;
    t[1]++;
    while(!coada.empty()){
        int varf=coada.front();
        viz[varf]=0;
        coada.pop();
        for(i=0;i<G[varf].size();i++){
            if(d[G[varf][i]]>d[varf]+C[varf][i]){
                d[G[varf][i]]=d[varf]+C[varf][i];
                if(viz[G[varf][i]]==0){
                    if(t[G[varf][i]]>n){
                        g<<"Ciclu negativ!";
                        return ;
                    }
                    else{
                        viz[G[varf][i]]=1;
                        t[G[varf][i]]++;
                        coada.push(G[varf][i]);
                    }
                }
            }
        }
    }
    for(i=2;i<=n;i++)
        if(d[i]==INF)
            g<<0<<' ';
        else
            g<<d[i]<<' ';
}
int main(){
    citire();
    bellman_ford();
    return 0;
}