Cod sursa(job #787320)

Utilizator stefanzzzStefan Popa stefanzzz Data 13 septembrie 2012 10:16:43
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <fstream>
#include <vector>
#include <queue>
#define INF 1000000000
#define MAXN 50005
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

struct muchie{
    int nod,cost;};

int n,m,x,y,d[MAXN],rang[MAXN];
vector<muchie> G[MAXN];
muchie aux;
queue<int> q;
bool uz[MAXN];

int main()
{
    int i;
    f>>n>>m;
    for(i=1;i<=m;i++){
        f>>x>>aux.nod>>aux.cost;
        G[x].push_back(aux);}
    for(i=2;i<=n;i++)
        d[i]=INF;
    rang[1]=1;
    q.push(1);
    while(!q.empty()){
        x=q.front();
        q.pop();
        if(rang[x]>n){
            g<<"Ciclu negativ!";
            return 0;}
        uz[x]=0;
        y=rang[x]+1;
        for(i=0;i<G[x].size();i++){
            if(d[x]+G[x][i].cost<d[G[x][i].nod]){
                d[G[x][i].nod]=d[x]+G[x][i].cost;
                if(!uz[G[x][i].nod]){
                    uz[G[x][i].nod]=1;
                    q.push(G[x][i].nod);}
                rang[G[x][i].nod]=y;}}}
    for(i=2;i<=n;i++)
        g<<d[i]<<' ';
    f.close();
    g.close();
    return 0;
}