Cod sursa(job #1136134)

Utilizator gabrielinelusGabriel-Robert Inelus gabrielinelus Data 8 martie 2014 19:58:08
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.41 kb
#include <cstdio>
#include <vector>
#include <queue>
#include <cstdlib>
#include <memory.h>
#include <bitset>

#define Nmax 50005
#define INF 0x3f3f3f3f

using namespace std;
vector<pair<int,int> > G[Nmax];
queue<int> Q;
bitset<Nmax>inQ;
int N,M,used[Nmax],D[Nmax];

void read()
{
    scanf("%d%d",&N,&M);
    int a,b,c;
    for(int i = 1; i <= M; ++i)
    {
        scanf("%d%d%d",&a,&b,&c);
        G[a].push_back(make_pair(c,b));
    }
}

void bellman_ford(int k)
{
    memset(D,INF,sizeof(D));
    Q.push(k);
    D[k] = 0;
    while(!Q.empty())
    {
        k = Q.front(); Q.pop();
        inQ[k] = 0;
        for(vector<pair<int,int> >::iterator it = G[k].begin(); it != G[k].end(); ++it)
            if(D[it->second] > D[k] + it->first)
            {
                D[it->second] = D[k] + it->first;
                if(!inQ[it->second])
                    Q.push(it->second);
                used[it->second] ++;
                if(used[it->second] > n)
                {
                    printf("Ciclu negativ!\n");
                    exit(0);
                }
            }
    }
    for(int i = 2; i <= N; ++i)
        if(D[i] == INF)
            printf("0 ");
        else
            printf("%d ",D[i]);
}

int main()
{
    freopen("bellmanford.in","r",stdin);
    freopen("bellmanford.out","w",stdout);

    read();
    bellman_ford(1);

    return 0;
}