Cod sursa(job #2106811)

Utilizator malina2109Malina Diaconescu malina2109 Data 16 ianuarie 2018 11:48:07
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.07 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <climits>
using namespace std;
ifstream f("bellmanford.in");
ofstream gg("bellmanford.out");
vector< pair<int,int> > g[50001];
queue<int> c;
int n,m;
int d[50001],nr[50001];
int main()
{
    int ok=1;
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        g[x].push_back(make_pair(y,c));
    }
    for(int i=1;i<=n;i++)
        d[i]=INT_MAX;
    d[1]=0;
    c.push(1);
    while(!c.empty()&&ok)
    {
        int var=c.front();
        c.pop();
        vector< pair<int,int> >::iterator it;
        for(it=g[var].begin();it!=g[var].end();++it)
            if(d[it->first]>d[var]+it->second)
        {
            d[it->first]=d[var]+it->second;
            nr[it->first]++;
            c.push(it->first);
            if(nr[it->first]>n)  ok=0;
        }
    }
    if(ok)
    {
        for(int i=2;i<=n;i++)
            if(d[i]<INT_MAX) gg<<d[i]<<" ";
        else gg<<0<<" ";
    }
    else gg<<"Ciclu negativ!";
    return 0;
}