刚学OI一秒钟，求问树状数组

void Upd(int x, long long v) {
  for (; x; x -= x & -x) {
    t[x] = max(t[x], v);
  }
}

long long Ask(int x) {
  long long r = 0;
  for (; x <= n; x += x & -x) {
    r = max(r, t[x]);
  }
  return r;
}