Cod sursa(job #2425781)

Utilizator dana.dascalescuDana Dascalescu dana.dascalescu Data 25 mai 2019 01:27:41
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include<bits/stdc++.h>
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

const int inf = 1e6;
int N, M, X, Y, cost;

int main()
{
    fin>>N>>M;
    vector<vector<pair<int,int> > > L(N+1);
    for(int i = 1; i <= M; i++)
    {
        fin>>X>>Y>>cost;
        L[X].push_back(make_pair(cost,Y));
    }
    fin.close();

    vector<int> dist(N+1,inf);
    vector<int> cnt_in_queue(N+1);
    dist[1] = 0;
    queue<int> Q;
    Q.push(1);
    bool negative_cicle = false;
    while(!Q.empty() && !negative_cicle)
    {
        int node = Q.front();
        Q.pop();
        if(cnt_in_queue[node]>N){
            fout<<"Ciclu negativ!";
            negative_cicle = true;
            return 0;
        }
        cnt_in_queue[node]++;
        for(auto neighbour : L[node])
        {
            if(dist[node] + neighbour.first < dist[neighbour.second])
            {
                dist[neighbour.second] = dist[node] + neighbour.first;
                Q.push(neighbour.second);
            }
        }
    }
    for(int i = 2; i <= N; i++)
        fout<<dist[i]<<' ';
    fout.close();
    return 0;
}