Cod sursa(job #2853168)

Utilizator rARES_4Popa Rares rARES_4 Data 19 februarie 2022 23:10:29
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <iostream>
#include <fstream>
#include <queue>
#include<vector>
using namespace std;
ifstream f ("bellmanford.in");
ofstream g ("bellmanford.out");
int n,m;
int fr[50001],dist[50001];
queue<pair<int,int>>q;
vector<pair<int,int>>adiacenta[50001];
void citire()
{
    f >> n >> m;
    for(int i = 1; i<=m; i++)
    {
        int x,y,c;
        f >> x >> y >> c;
        adiacenta[x].push_back({y,c});
    }
}
void init()
{
    for(int i = 1; i<=n; i++)
        dist[i] = (1<<30)-1;
}
void bellman()
{
    q.push({0,1});
    fr[1] = 1;
    dist[1] = 0;
    while(!q.empty())
    {
        int nod_curent = q.front().second;
        int cost_curent = q.front().first;
        q.pop();

        for(auto x:adiacenta[nod_curent])
        {
            int vecin = x.first;
            int cost = x.second;

            if(dist[vecin]>dist[nod_curent]+cost)
            {
                dist[vecin] = cost+dist[nod_curent];
                fr[vecin]++;
                q.push({dist[vecin],vecin});
            }
            if(fr[vecin]>=n+1)
            {
                g << "Ciclu negativ!";
                exit(0);
            }
        }
    }
}
void afisare()
{
    for(int i = 2; i<=n; i++)
        g << dist[i]<< " ";
}
int main()
{
    citire();
    init();
    bellman();
    afisare();
}