Cod sursa(job #1881301)

Utilizator gabib97Gabriel Boroghina gabib97 Data 16 februarie 2017 12:46:37
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <stdio.h>
#include <vector>
#include <queue>
#include <stdlib.h>
#define N 50001
#define inf 100000000
#define pp pair<int,int>
using namespace std;

int n,m,i,x,y,c,d[N],f[N];
bool o[N];
vector<pp> G[N];
queue<int> Q;

void bellman_ford()
{
    int i,x,y;
    for (i=2;i<=n;i++) d[i]=inf;
    Q.push(1);
    o[1]=1;

    while(!Q.empty())
    {
        x=Q.front();
        Q.pop();
        o[x]=0;

        for (i=0;i<G[x].size();i++)
        {
            y=G[x][i].first;
            if (d[y]>d[x]+G[x][i].second)
            {
                d[y]=d[x]+G[x][i].second;
                if (!o[y])
                {
                    o[y]=1;
                    f[y]++;
                    Q.push(y);
                    if (f[y]>n) printf("Ciclu negativ!"),exit(0);
                }
            }
        }
    }
}

int main()
{
    freopen ("bellmanford.in","r",stdin);
    freopen ("bellmanford.out","w",stdout);
    scanf("%i%i",&n,&m);
    for (i = 1; i <= m; i++)
    {
        scanf("%i%i%i",&x,&y,&c);
        G[x].push_back(make_pair(y,c));
    }
    bellman_ford();
    for (i=2;i<=n;i++)
        printf("%i ",d[i]==inf?0:d[i]);
    fclose(stdin);
    fclose(stdout);
    return 0;
}