主席树0ptsMLE12345WA6求助

#include <iostream>

using namespace std;

const int kMaxN = 5e5 + 1;

int n, m, q, rt, a[kMaxN];
struct Node {
  int t, s, l, r;
} t[kMaxN];

void Update(int pre, int &k, int l, int r, int x) {
  if (r < x || l > x) {
    return;
  }
  k = ++rt;
  t[x].l = t[pre].l, t[x].r = t[pre].r, t[k].s = t[pre].s + 1;
  if (l == r) {
    return;
  }
  int m = l + r >> 1;
  Update(t[pre].l, t[k].l, l, m, x);
  Update(t[pre].r, t[k].r, m + 1, r, x);
}

int Query(int u, int v, int l, int r, int x, int y) {
  int num = t[v].s - t[u].s;
  int m = l + r >> 1;
  if (y < l || x > r || num == 0) {
    return 0;
  }
  return Query(t[u].l, t[v].l, l, m, x, y) + Query(t[u].r, t[v].r, m + 1, r, x, y);
}

int main() {
  cin >> n >> q;
  for (int i = 1; i <= n; i++) {
    cin >> a[i], m = max(m, a[i]);
  }
  for (int i = 1; i <= n; i++) {
    Update(t[i - 1].t, t[i].t, 0, m, a[i]);
  }
  for (int b, x, l, r, ans = 0; q; q--, ans = 0) {
    cin >> b >> x >> l >> r;
    for (int i = 18; i >= 0; i--) {
      if (b & (1 << i) && !Query(t[l - 1].t, t[r].t, 0, m, ans - x, ans - x + (1 << i) - 1)) {
        ans += (1 << i);
      }
      if (!(b & (1 << i)) && Query(t[l - 1].t, t[r].t, 0, m, ans - x + (1 << i), ans - x + (1 << (i + 1)) - 1)) {
        ans += (1 << i);
      }
    }
    cout << (ans ^ b) << '\n';
  }
  return 0;
}