Cod sursa(job #2572381)

Utilizator danin01Nastase Daniel danin01 Data 5 martie 2020 12:39:22
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <fstream>
#define nmax 50001
#define inf 1e9
#include <vector>
#include <queue>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
vector<pair<int,int> > v[nmax];
priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > >h;
int d[nmax],n,m,a,b,c,nod;
int w[nmax];
int main()
{
    int i;
 
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>a>>b>>c;
        v[a].push_back(make_pair(c,b));
    }
    for(i=1; i<=n; i++)
        d[i]=inf;
    d[1]=0;
    h.push(make_pair(0,1));
    while(!h.empty())
    {
        nod=h.top().second;
        h.pop();
        for(i=0; i<v[nod].size(); i++)
        {
            if(d[nod]+v[nod][i].first<d[v[nod][i].second])
            {
                w[v[nod][i].second]++;
                d[v[nod][i].second]=d[nod]+v[nod][i].first;
                h.push(make_pair(d[v[nod][i].second],v[nod][i].second));
                if(w[v[nod][i].second]==n)
                {
                    g<<"Ciclu negativ!";
                    return 0;
                }
            }
        }
 
    }
 
    for(i=2; i<=n; i++)
    {
 
         g<<d[i]<<" ";
    }
    return 0;
}