Cod sursa(job #2138414)

Utilizator sulzandreiandrei sulzandrei Data 21 februarie 2018 17:07:23
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
#define maxm  250010
#define maxn  50010
int d[maxn];

struct edge
{
    int a,b,c;
};
vector<edge> v[maxn];
bool inserted[maxn]{false};
int used[maxn];
int main()
{
   int n,m;
   queue<int> que;
   edge e;
   in >> n >> m;
   for(int i = 0  ;i < m ; i++)
   {
       in >> e.a>>e.b>>e.c;
       v[e.a].push_back(e);
   }
   for(int i = 1 ; i<= n  ; i++)
    {
        d[i] = 1<<30;
        used[i] = 0;
        inserted[i] = false;
    }
    d[1] =0;
    que.push(1);
    inserted[1] = true;
    used[1] = 1;
    int nod;
    while(!que.empty() )
    {

        nod = que.front(); que.pop();
        inserted[nod] = true;
        for(edge nei:v[nod])
            if(d[nod]+nei.c < d[nei.b])
            {
                if(!inserted[nei.b])
                {
                    d[nei.b] = d[nod]+nei.c;
                    used[nei.b]++;
                    que.push(nei.b);
                    inserted[nei.b] =true;
                    if(used[nei.b]>=n)
                    {
                        out<< "Ciclu negativ!";
                        return 0;
                    }
                }
            }
    }
    for(int i = 2 ; i <= n ; i++)
        out<<((d[i]== 1<<30)?0:d[i])<<" ";
}