Cod sursa(job #1822577)

Utilizator NinjaCubeMihai Radovici NinjaCube Data 5 decembrie 2016 10:04:36
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <stdio.h>
#define INFINIT 500000000
#include <vector>
#include <queue>
using namespace std;
FILE *fin = fopen("bellmanford.in", "r");
FILE *fout = fopen("bellmanford.out", "w");
struct pereche
{
    int nod,cost;
};
vector <pereche> muchie[50001];
int optim[50001];
int cnt[50001];
char vizitat[50001];
int n,m,st,dr,cos;
int main()
{
    fscanf(fin, "%d%d", &n , &m);
    for(int i=1;i<=m;i++)
    {
        fscanf(fin, "%d%d%d", &st, &dr, &cos);
        muchie[st].push_back({dr,cos});
    }
    optim[1]=0;
    for(int i=2;i<=n;i++) optim[i]=INFINIT;
    queue <int> frontiera;
    frontiera.push(1);
    int ok=1;
    vizitat[1]=1;
    cnt[1]=1;
    while((!frontiera.empty()) && ok==1)
    {
        int nodul=frontiera.front();
        vizitat[nodul]=0;
        frontiera.pop();
        for(auto m:muchie[nodul])
        {
            if(optim[nodul]+m.cost<optim[m.nod])
            {
                optim[m.nod]=m.cost+optim[nodul];
                if(vizitat[m.nod]==0)
                {
                    vizitat[m.nod]=1;
                    cnt[m.nod]++;
                    if(cnt[m.nod]>n)ok=0;
                    frontiera.push(m.nod);
                }
            }
        }
    }
    if(ok==1)
    {
        for(int i=2;i<=n;i++)
        {
            fprintf(fout, "%d ", optim[i]);
        }
    }
    else fprintf(fout, "Ciclu negativ !");
    return 0;
}