Cod sursa(job #1883299)

Utilizator ChiriGeorgeChiriluta George-Stefan ChiriGeorge Data 17 februarie 2017 21:15:20
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>
#define NMAX 50005
#define Inf 0x3f3f3f3f

using namespace std;

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

struct edge{int to, cost;};
vector <edge> G[NMAX];
queue <int> Q;
int n, m, visited[NMAX], freq[NMAX], d[NMAX];
int main()
{
    int i, j, x, y, c,v, neigh;
    fin >> n >> m;
    for(i = 1; i <= m; i++)
    {
        fin >> x >> y >> c;
        edge p;
        p.to = y;
        p.cost = c;
        G[x].push_back(p);
    }
    memset(d, Inf, sizeof(d));
    Q.push(1);
    visited[1] = 1;
    d[1] = 0;
    while(!Q.empty())
    {
        v = Q.front();
        Q.pop();
        for(i = 0; i < G[v].size(); i++)
        {
            neigh = G[v][i].to;
            c = G[v][i].cost;
            if(d[neigh] > d[v] + c)
            {
                d[neigh] = d[v] + c;
                if(visited[neigh] == 0)
                {
                    Q.push(neigh);
                    visited[neigh] = 1;
                    if(++freq[neigh] >= n)
                    {
                        fout << "Ciclu negativ!" <<'\n';
                        return 0;
                    }
                }
            }
        }
    }
    for(i = 2; i <= n; i++)
        fout << d[i] << ' ';
    fout << '\n';
    return 0;
}