Cod sursa(job #2576268)

Utilizator danhHarangus Dan danh Data 6 martie 2020 18:13:00
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

vector<pair<int, int> > v[50005];
queue<int> q;

const int inf = 0x3f3f3f3f;

int dist[50005];
int pred[50005];
int cnt[50005];
int n, m;
bool viz[50005];

int main()
{
    int i, j, x, y, c;
    fin>>n>>m;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y>>c;
        v[x].push_back({y, c});
    }
    for(i=2; i<=n; i++)
    {
        dist[i] = inf;
    }

    q.push(1);
    viz[1] = true;
    cnt[1] = 1;
    while(!q.empty())
    {
        x = q.front();
        q.pop();
        viz[x] = false;
        for(pair<int, int> el : v[x])
        {
            int nod = el.first, cost = el.second;
            if(dist[nod] > dist[x] + cost)
            {
                dist[nod] = dist[x] + cost;
                if(!viz[nod])
                {
                    viz[nod] = true;
                    cnt[nod]++;
                    if(cnt[nod] > n)
                    {
                        fout<<"Ciclu negativ!";
                        fin.close();
                        fout.close();
                        return 0;
                    }
                    q.push(nod);
                }
            }
        }
    }

    for(i=2; i<=n; i++)
    {
        fout<<dist[i]<<' ';
    }
    fin.close();
    fout.close();
    return 0;
}