Problem p00998 (C++) — buggy submission, verdict: Runtime Error

#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <tuple>
#include <utility>
#include <vector>
#define loop(i, a, b) for (int i = (a); i < int(b); i++)
#define rep(i, n) loop(i, 0, n)

using namespace std;

int const inf = 1e9;
#define np nullptr

struct Node {
  int val;
  Node *ch[2];
  int pri, cnt, sum;
  int min;
  Node(int v, int p) : val(v), pri(p), cnt(1), sum(v), min(v) {
    ch[0] = ch[1] = np;
  }
  // ~Node(){
  //     if(ch[0]) delete ch[0];
  //     if(ch[1]) delete ch[1];
  // }
  void *operator new(size_t sz) {
    static int pos = 0;
    static char mem[400020 * sizeof(Node)];
    Node *res = (Node *)(mem + pos);
    pos += sizeof(Node);
    return res;
  }
};

int count(Node *t) { return t == np ? 0 : t->cnt; }
int sum(Node *t) { return t == np ? 0 : t->sum; }
int min(Node *t) { return t == np ? inf : t->min; }

void show(Node *n, int ofs = 0) {
  if (n == nullptr)
    return;
  show(n->ch[0], ofs + 1);
  rep(i, ofs * 2) putchar(' ');
  printf("v:%d m:%d (%p)\\n", n->val, n->min, n);
  show(n->ch[1], ofs + 1);
}

void update(Node *t) {
  t->cnt = count(t->ch[0]) + count(t->ch[1]) + 1;
  t->sum = sum(t->ch[0]) + sum(t->ch[1]) + t->val;
  t->min = min({min(t->ch[0]), min(t->ch[1]), t->val});
}

Node *merge(Node *l, Node *r) {
  if (l == np || r == np)
    return l == np ? r : l;
  if (l->pri > r->pri) {
    l->ch[1] = merge(l->ch[1], r);
    update(l);
    return l;
  } else {
    r->ch[0] = merge(l, r->ch[0]);
    update(r);
    return r;
  }
}

pair<Node *, Node *> split(Node *t, int k) {
  if (t == np)
    return make_pair(np, np);
  if (k <= count(t->ch[0])) {
    auto s = split(t->ch[0], k);
    t->ch[0] = s.second;
    update(t);
    return make_pair(s.first, t);
  } else {
    k -= count(t->ch[0]) + 1;
    auto s = split(t->ch[1], k);
    t->ch[1] = s.first;
    update(t);
    return make_pair(t, s.second);
  }
}

Node *erase(Node *t, int k) {
  Node *l, *m, *r;
  tie(l, m) = split(t, k);
  tie(m, r) = split(m, 1);
  // delete m;
  return merge(l, r);
}

Node *at(Node *t, int k) {
  int lc = count(t->ch[0]);
  if (k < lc)
    return at(t->ch[0], k);
  else if (k == lc)
    return t;
  else
    return at(t->ch[1], k - lc - 1);
}

Node *insert(Node *t, int k, int v) {
  Node *l, *m = new Node(v, rand()), *r;
  tie(l, r) = split(t, k);
  return merge(merge(l, m), r);
}

int min(Node *t, int l, int r) {
  if (r - l <= 0)
    return inf;
  if (r - l == count(t))
    return min(t);
  int s = count(t->ch[0]);
  if (l == s && r - s == 1)
    return t->val;
  int res = inf;
  if (l < s)
    res = min(res, min(t->ch[0], l, min(s, r)));
  if (l <= s && s < r)
    res = min(res, min(t, s, s + 1));
  if (s + 1 < r)
    res = min(res, min(t->ch[1], max(0, l - s - 1), r - s - 1));
  return res;
}

int get() {
  int x;
  scanf("%d", &x);
  return x;
}
void put(int x) {
  // printf("ans : %d\\n",x);
  printf("%d\\n", x);
}

int main() {
#ifdef DEBUG
  freopen("in", "r", stdin);
#endif
  srand(time(0));
  int n = get(), q = get();
  Node *root = np;
  rep(i, n) root = insert(root, i, get());

  rep(i, q) {
    int op = get();
    if (false) {
    } else if (op == 0) {
      int l = get(), r = get();
      int x = at(root, r)->val;
      root = erase(root, r);
      root = insert(root, l, x);
    } else if (op == 1) {
      int l = get(), r = get();
      r++;
      put(min(root, l, r));
    } else if (op == 2) {
      int p = get(), v = get();
      root = erase(root, p);
      root = insert(root, p, v);
    }
  }
  // delete root;
}

Error: 0

Fixed submission:

#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <tuple>
#include <utility>
#include <vector>
#define loop(i, a, b) for (int i = (a); i < int(b); i++)
#define rep(i, n) loop(i, 0, n)

using namespace std;

int const inf = 1e9;
#define np nullptr

struct Node {
  int val;
  Node *ch[2];
  int pri, cnt, sum;
  int min;
  Node(int v, int p) : val(v), pri(p), cnt(1), sum(v), min(v) {
    ch[0] = ch[1] = np;
  }
  // ~Node(){
  //     if(ch[0]) delete ch[0];
  //     if(ch[1]) delete ch[1];
  // }
  void *operator new(size_t sz) {
    static int pos = 0;
    static char mem[200020 * sizeof(Node)];
    Node *res = (Node *)(mem + pos);
    pos += sizeof(Node);
    return res;
  }
};

int count(Node *t) { return t == np ? 0 : t->cnt; }
int sum(Node *t) { return t == np ? 0 : t->sum; }
int min(Node *t) { return t == np ? inf : t->min; }

void show(Node *n, int ofs = 0) {
  if (n == nullptr)
    return;
  show(n->ch[0], ofs + 1);
  rep(i, ofs * 2) putchar(' ');
  printf("v:%d m:%d (%p)\\n", n->val, n->min, n);
  show(n->ch[1], ofs + 1);
}

void update(Node *t) {
  t->cnt = count(t->ch[0]) + count(t->ch[1]) + 1;
  t->sum = sum(t->ch[0]) + sum(t->ch[1]) + t->val;
  t->min = min({min(t->ch[0]), min(t->ch[1]), t->val});
}

Node *merge(Node *l, Node *r) {
  if (l == np || r == np)
    return l == np ? r : l;
  if (l->pri > r->pri) {
    l->ch[1] = merge(l->ch[1], r);
    update(l);
    return l;
  } else {
    r->ch[0] = merge(l, r->ch[0]);
    update(r);
    return r;
  }
}

pair<Node *, Node *> split(Node *t, int k) {
  if (t == np)
    return make_pair(np, np);
  if (k <= count(t->ch[0])) {
    auto s = split(t->ch[0], k);
    t->ch[0] = s.second;
    update(t);
    return make_pair(s.first, t);
  } else {
    k -= count(t->ch[0]) + 1;
    auto s = split(t->ch[1], k);
    t->ch[1] = s.first;
    update(t);
    return make_pair(t, s.second);
  }
}

Node *erase(Node *t, int k) {
  Node *l, *m, *r;
  tie(l, m) = split(t, k);
  tie(m, r) = split(m, 1);
  // delete m;
  return merge(l, r);
}

Node *at(Node *t, int k) {
  int lc = count(t->ch[0]);
  if (k < lc)
    return at(t->ch[0], k);
  else if (k == lc)
    return t;
  else
    return at(t->ch[1], k - lc - 1);
}

Node *insert(Node *t, int k, int v) {
  Node *l, *m = new Node(v, rand()), *r;
  tie(l, r) = split(t, k);
  return merge(merge(l, m), r);
}

int min(Node *t, int l, int r) {
  if (r - l <= 0)
    return inf;
  if (r - l == count(t))
    return min(t);
  int s = count(t->ch[0]);
  if (l == s && r - s == 1)
    return t->val;
  int res = inf;
  if (l < s)
    res = min(res, min(t->ch[0], l, min(s, r)));
  if (l <= s && s < r)
    res = min(res, min(t, s, s + 1));
  if (s + 1 < r)
    res = min(res, min(t->ch[1], max(0, l - s - 1), r - s - 1));
  return res;
}

int get() {
  int x;
  scanf("%d", &x);
  return x;
}
void put(int x) {
  // printf("ans : %d\\n",x);
  printf("%d\\n", x);
}

int main() {
#ifdef DEBUG
  freopen("in", "r", stdin);
#endif
  srand(time(0));
  int n = get(), q = get();
  Node *root = np;
  rep(i, n) root = insert(root, i, get());

  rep(i, q) {
    int op = get();
    if (false) {
    } else if (op == 0) {
      int l = get(), r = get();
      int x = at(root, r)->val;
      root = erase(root, r);
      root = insert(root, l, x);
    } else if (op == 1) {
      int l = get(), r = get();
      r++;
      put(min(root, l, r));
    } else if (op == 2) {
      int p = get(), v = get();
      root = erase(root, p);
      root = insert(root, p, v);
    }
  }
  // delete root;
}