站外题

int n, m, q, f[1001][1001];
void sovel()
{
    cin >> n >>  q;
    memset(f, 127, sizeof(f));
    rep(i, 1, n) f[i][i] = 0;
    rep(i, 1, n)
    {
        int x, y;
        x = read(), y = read();
        if(x==y)continue;
        f[x][y] = 1;
        f[y][x] = 1;
    }
    rep(k, 1, n)
        rep(i, 1, n)
            rep(j, 1, n) if (f[i][k] < 1 << 30 && f[k][j] < 1 << 30)
                f[i][j] = min(f[i][j], f[i][k] + f[k][j]);
    rep(i, 1, q)
    {
        int s, t;
        s = read(), t = read();
        if (f[s][t] < 1 << 30)
            printf("%d\n", f[s][t]);
        else
            puts("-1");
    }
}