Cod sursa(job #884514)

Utilizator CosminnnChirica Cosmin Cosminnn Data 20 februarie 2013 22:56:46
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define INF 2000000000
using namespace std;

int n,m,d[50010],ordin[50010];

struct NOD
{
    int x,cost;
};
vector <NOD> L[50010];
queue <int> q;

inline void Read()
{
    int i,x;
    NOD aux;
    freopen("bellmanford.in","r",stdin);
    scanf("%d %d", &n, &m);
    for( i=1; i<=m; i++ )
    {
        scanf("%d %d %d",&x,&aux.x,&aux.cost);
        L[x].push_back(aux);
    }
}

inline bool BellmanFord()
{
    int i,x,pr,ul;
    NOD aux;
    for(i=1; i<=n ;i++)
        d[i]=INF;
    d[1]=0;

    q.push(1);
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(i=0;i<L[x].size();i++)
        {
            aux=L[x][i];
            if(d[aux.x]>d[x]+aux.cost)
            {
                q.push(aux.x);
                d[aux.x]=d[x]+aux.cost;
                ordin[aux.x] = ordin[x] + 1;

                if (ordin[aux.x] > n)
                    return true;
            }
        }
    }
    return false;
}

inline void Write(bool ciclu)
{
    freopen("bellmanford.out","w",stdout);
    if(ciclu)
    {
        printf("Ciclu negativ!\n");
    }
    else
    {
        int i;
        for(i=2; i<=n; i++)
           printf("%d ",d[i]);
        printf("\n");
    }
}
int main()
{
    bool ciclu;

    Read();
    ciclu=BellmanFord();
    Write(ciclu);

    return 0;
}