并查集

并查集
void make(int x)
{
    for (int i = 0; i <= x; i++)
        p[i] = i;
}
int find(int x)
{
    if (x != p[x])
        p[x] = find(p[x]);
    return p[x];
}
void unio(int x, int y)
{
    int px = find(x);
    int py = find(y);
    if (px == py)
        return;
    p[px] = py;
}
bool same(int x, int y)
{
    return find(x) == find(y);
}