Cod sursa(job #1494532)

Utilizator DiClauDan Claudiu DiClau Data 1 octombrie 2015 12:38:04
Problema Sortare topologica Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include<stdio.h>
using namespace std;
const int N = 50001, M = 100001;
int vf[M], lst[N], urm[M];
int nr = 0, coada[N], pre[N*2], inceput, sf;
void adauga(int x, int y)
{
    nr++;
    vf[nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
}
void bfs()
{
    int p, y;
    while (inceput < sf)
    {
        p = lst[coada[inceput]];
        while (p != 0)
        {

            y = vf[p];
            pre[y]--;
            if (pre[y] == 0)
                coada[sf++] = y;
            p = urm[p];
        }
        inceput++;
    }
}
int main ()
{
    FILE *in, *out;
    in = fopen ("sortaret.in", "r");
    out = fopen ("sortaret.out", "w");
    int n, m, c = 0;
    fscanf (in, "%d%d", &n, &m);
    int i, x, y;
    for (i = 1; i <= m; i++)
    {
        fscanf (in, "%d%d", &x, &y);
        adauga(x, y);
        pre[y]++;
    }
    for (i = 1; i <= n; i++)
        if (pre[i] == 0)
            coada[sf++] = i;
    bfs();
    for (i = 0; i < sf; i++)
        fprintf (out, "%d ", coada[i]);
    return 0;
}