Cod sursa(job #1577655)

Utilizator GuzgleteBumbu Alexandru Guzglete Data 23 ianuarie 2016 17:46:04
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <iostream>
#include <vector>
#include <queue>
#include <climits>
#define inf INT_MAX/2
#include <fstream>

using namespace std;

ifstream fin ("bellmanford.in");
ofstream fout ("bellmanford.out");
vector < pair < int,int > > lv[50001];
vector < pair < int,int > >:: iterator ii;
queue <int> q;
int d[50001];
int isinq[500001];
int counter[50001];

int main()
{
    int n, m;
    int x,y,c;
    fin>>n>>m;
    for (int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        lv[x].push_back(make_pair(y,c));
    }
    for (int i=1;i<=n;i++)
        d[i]=inf;
    d[1]=0;
    q.push(1);
    isinq[1]++;
    while (!q.empty())
    {
        x=q.front();
        if (counter[x]>n)
            break;
        q.pop();
        isinq[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 (isinq[ii->first]==0)
                {
                    q.push(ii->first);
                    isinq[ii->first]=1;
                    counter[ii->first]++;
                }
            }
    }
    if (!q.empty())
        fout<<"Ciclu negativ!";
    else
        for (int i=2;i<=n;i++)
            if (d[i]==inf)
                fout<<"0 ";
            else
                fout<<d[i]<<" ";

    return 0;
}