Cod sursa(job #1576905)

Utilizator doruliqueDoru MODRISAN dorulique Data 22 ianuarie 2016 22:38:38
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include<cstdio>
#include<vector>
#include<queue>
#include<climits>
#define inf INT_MAX/2
using namespace std;

vector <pair<int,int> > lv[50001];
bool used[50001];
queue <int> q;
vector <pair<int,int> >::iterator ii;
int d[50001],nrap[50001];
int main()
{
    FILE *f=fopen("bellmanford.in","r");
    int n,m,i,x,y,c;
    fscanf(f,"%d%d",&n,&m);
    for(i=1; i<=m; i++)
    {
        fscanf(f,"%d%d%d",&x,&y,&c);
        lv[x].push_back(make_pair(y,c));
    }
    f=fopen("bellmanford.out","w");
    for(i=1;i<=n;i++)d[i]=inf;
    int start=1;
    d[start]=0;
    used[start]=1;
    q.push(start);
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        used[x]=0;
        for(ii=lv[x].begin(); ii!=lv[x].end(); ii++)
            if(d[x]+ii->second<d[ii->first])
            {
                d[ii->first]=d[x]+ii->second;
                if(!used[ii->first])
                {
                    used[ii->first]=1;
                    q.push(ii->first);
                    nrap[ii->first]++;
                    if(nrap[ii->first]>n)
                    {
                        fprintf(f,"Ciclu negativ!");
                        return 0;
                    }
                }
            }
    }
    f=fopen("bellmanford.out","w");
    for(i=2;i<=n;i++)
        fprintf(f,"%d ",d[i]==inf?0:d[i]);
    return 0;
}