Cod sursa(job #1400843)

Utilizator AnduuFMI Alexandru Banu Anduu Data 25 martie 2015 14:47:56
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <vector>
#include <queue>
#include <climits>
#define INF INT_MAX
#define NMAX 50001
using namespace std;

struct arc {int y, c;};
bool viz[NMAX];
int nr[NMAX];

vector<arc> v[9];

int main() {
    int n, d[NMAX], m, x, negativ = 0, i;
    arc z;
    queue<int> l;

    ifstream in("bellmanford.in");
    in >> n >> m;
    for (i = 1; i <= m; i++) {
        in >> x >> z.y >> z.c;
        v[x].push_back(z);
    }
    in.close();

    /*for (i = 1; i <= n; i++)
        for (vector<arc>::iterator it = v[i].begin(); it != v[i].end(); it++)
            out << i << ' ' << it->y << ' ' << it->c << ' ';*/

    for (i = 1; i <= n; i++)
        d[i] = INF;
    d[1] = 0;
    l.push(1);
    viz[1] = 1;
    while (!l.empty() && !negativ) {
        for (vector<arc>::iterator it = v[l.front()].begin(); it != v[l.front()].end(); it++)
            if (d[it->y] > d[l.front()] + d[it->c]) {
                d[it->y] = d[l.front()] + d[it->c];
                if (!viz[it->y]) {
                    if (nr[it->y] == n)
                        negativ = 1;
                    l.push(it->y);
                    viz[it->y] = 1;
                    nr[it->y]++;
                }
            }
        viz[l.front()] = 0;
        l.pop();
    }

    ofstream out("bellmanford.out");
    if (negativ)
        out << "Ciclu negativ!";
    else for (i = 2; i <= n; i++)
            out << d[i] << ' ';
    out.close();

    return 0;
}