Cod sursa(job #2158891)

Utilizator IustinPetrariuIustinian Petrariu IustinPetrariu Data 10 martie 2018 16:56:20
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.46 kb
#include <iostream>
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
#define inf 0x3f3f3f
#define nmax 250001
#define mmax 50005
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
vector < pair < int, int > > v[nmax];
queue<int>coada;
int n,m,x,y,z,d[mmax],inqueue[mmax],varf,nr[mmax];
void read()
{
    fin>>n>>m;
    for(int i =1 ; i <= m ; i++)
    {
        fin>>x>>y>>z;
        v[x].push_back(make_pair(y,z));
    }
}
int main()
{
    read();
    for(int i =2 ; i <= n ; i++)
        d[i]=inf;
    d[1]=0;
    coada.push(1);
    inqueue[1]=1;
    while(!coada.empty())
    {
        int varf=coada.front();
        coada.pop();
        inqueue[varf]=0;
        for(int i = 0 ; i < v[varf].size(); i++)
            if(d[varf]+v[varf][i].second < d[v[varf][i].first])
            {
                d[v[varf][i].first]=d[varf]+v[varf][i].second;
                if(inqueue[v[varf][i].first]==0)
                {
                    coada.push(v[varf][i].first);
                    inqueue[v[varf][i].first]=1;
                            nr[v[varf][i].first]++;
                            if(nr[v[varf][i].first]==n)
                    {
                        fout<<"Ciclu negativ!";
                        return 0;
                    }
                }
            }
    }
    for(int i =2; i <= n ; i++)
        fout<<d[i]<<" ";
        fout<<'\n';
    return 0;
}