Problem p02347 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <algorithm>
#include <cstdio>
#include <vector>
using namespace std;
struct Node {
  int location;
  int p, l, r;
  Node() { l = r = p = -1; }
};
struct Point {
  int id, x, y;
  Point() {}
  Point(int id, int x, int y) : id(id), x(x), y(y) {}
  bool operator<(const Point &p) const { return id < p.id; }
  void print() { printf("%d\\n", id); }
};
const int MAX_N = 500000;
int N;
Point P[MAX_N * 2];
Node T[MAX_N * 2];
int np;
bool lessX(const Point &p1, const Point &p2) { return p1.x < p2.x; }
bool lessY(const Point &p1, const Point &p2) { return p1.y < p2.y; }
int build(int depth, int l, int r) {
  if (l >= r)
    return -1;
  int mid = (l + r) >> 1;
  int t = np++;
  if (depth % 2 == 0)
    sort(P + l, P + r, lessX);
  else
    sort(P + l, P + r, lessY);
  T[t].location = mid;
  T[t].l = build(depth + 1, l, mid);
  T[t].r = build(depth + 1, mid + 1, r);
  return t;
}
vector<Point> ans;
void find(int v, int sx, int tx, int sy, int ty, int depth) {
  int x = P[T[v].location].x;
  int y = P[T[v].location].y;
  if (sx <= x && x <= tx && sy <= y && y <= ty)
    ans.push_back(P[T[v].location]);
  if (depth % 2 == 0) {
    if (T[v].l != -1)
      if (sx <= x)
        find(T[v].l, sx, tx, sy, ty, depth + 1);
    if (T[v].r != -1)
      if (x <= tx)
        find(T[v].r, sx, tx, sy, ty, depth + 1);
  } else {
    if (T[v].l != -1)
      if (sy <= y)
        find(T[v].l, sx, tx, sy, ty, depth + 1);
    if (T[v].r != -1)
      if (y <= ty)
        find(T[v].r, sx, tx, sy, ty, depth + 1);
  }
}
int main() {
  int x, y;
  scanf("%d", &N);
  for (int i = 0; i < N; i++) {
    scanf("%d %d", &x, &y);
    P[i] = Point(i, x, y);
  }
  np = 0;
  int root = build(0, 0, N);
  int q;
  scanf("%d", &q);
  int sx, tx, sy, ty;
  for (int i = 0; i < q; i++) {
    scanf("%d %d %d %d", &sx, &tx, &sy, &ty);
    ans.clear();
    find(root, sx, tx, sy, ty, 0);
    sort(ans.begin(), ans.end());
    for (int j = 0; j < ans.size(); j++)
      ans[j].print();
    printf("\\n");
  }
  return 0;
}

Error: MLE

Fixed submission:

#include <algorithm>
#include <iostream>
#include <math.h>
#include <stdio.h>
#include <vector>
// I LOVE IT :D
// #define int long long
using namespace std;
inline int in() {
  int32_t x;
  scanf("%d", &x);
  return x;
}
inline string getStr() {
  char ch[1000000];
  scanf("%s", ch);
  return ch;
}
const int MAX_N = 500001;
const int MAX_LG = 17;
pair<int, int> x[MAX_N];
int y[MAX_N];
pair<int, int> st[MAX_LG][MAX_N];
void build(int dep, int l, int r) {
  if (l == r) {
    st[dep][l] = {y[x[l].second], x[l].second};
    return;
  }
  int mid = (l + r) >> 1;
  build(dep + 1, l, mid);
  build(dep + 1, mid + 1, r);
  merge(st[dep + 1] + l, st[dep + 1] + mid + 1, st[dep + 1] + mid + 1,
        st[dep + 1] + r + 1, st[dep] + l);
}
int j;
vector<int> result;
inline void query(int dep, int l, int r, int x1, int y1, int x2, int y2) {
  if (x[r].first < x1 || x[l].first > x2)
    return;
  if (st[dep][l].first > y2 || st[dep][r].first < y1)
    return;
  if (x[l].first >= x1 && x[r].first <= x2) {
    if (st[dep][l].first >= y1 && st[dep][r].first <= y2) {
      for (j = l; j <= r; j++)
        result.push_back(st[dep][j].second);
      return;
    }
  }
  int mid = (l + r) >> 1;
  query(dep + 1, l, mid, x1, y1, x2, y2);
  query(dep + 1, mid + 1, r, x1, y1, x2, y2);
  return;
}
int32_t main() {
  int n = in();
  for (int i = 0; i < n; i++) {
    x[i] = {in(), i};
    y[i] = in();
  }
  sort(x, x + n);
  build(0, 0, n - 1);
  int q = in();
  int x1, x2, y1, y2;

  while (q--) {
    x1 = in(), x2 = in(), y1 = in(), y2 = in();
    result.clear();
    query(0, 0, n - 1, x1, y1, x2, y2);
    sort(result.begin(), result.end());
    for (j = 0; j < result.size(); j++)
      cout << result[j] << "\\n";
    cout << "\\n";
  }
}