Parcurgerea in latime

#include <iostream>
#include <fstream>
#include <stdlib.h>

using namespace std;

int a[100][100], viz[100];

int main() {
    int n, m, x, y, vf, p, u, c[100];
    ifstream f("date.in");
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        f >> x >> y;
        a[x][y] = 1; a[y][x] = 1;
    }
    f >> vf;
    viz[vf] = 1;
    p = 1;
    u = 1;
    c[1] = vf;
    while (p <= u) {
        vf = c[p];
        for (int i = 1; i <= n; i++)
            if (a[vf][i] == 1 && viz[i] == 0) {
                u++;
                c[u] = i;
                viz[i] = 1;
            }
        p++;
    }
    for (int i = 1; i <= u; i++)
        cout << c[i] << " ";
    f.close();
    system("pause");
}