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

#include <bits/stdc++.h>

class Node {
public:
  Node() : left(nullptr), right(nullptr) {}
  int val;
  int min;
  int num;
  int rank;
  Node *left, *right;
};

void dump(Node *p) {
  if (p == nullptr) {
    fprintf(stderr, "(nil)");
    return;
  }
  if (p->left == nullptr and p->right == nullptr) {
    fprintf(stderr, "{n%d}(%d)", p->num, p->val);
    return;
  }
  fprintf(stderr, "{n%d,r%d,m%d}[", p->num, p->rank, p->min);
  dump(p->left);
  fprintf(stderr, ",");
  dump(p->right);
  fprintf(stderr, "]");
}

void dumpLine(Node *p) {
  return;
  dump(p);
  puts("");
}

template <typename T, int chunksize = 262144> class Heap {
public:
  Heap() : n(chunksize) {}
  std::vector<T *> ptrs;
  std::stack<T *> stack;
  int n;
  T *next() {
    if (not stack.empty()) {
      T *res = stack.top();
      stack.pop();
      return res;
    }
    if (n == chunksize) {
      T *p = new T[chunksize];
      ptrs.push_back(p);
      n = 0;
    }
    T *res = &ptrs[ptrs.size() - 1][n];
    n += 1;
    return res;
  }
  void push(T *p) { stack.push(p); }
};
Heap<Node> heap;

Node *initNode(int val) {
  Node *p = heap.next();
  p->left = p->right = nullptr;
  p->min = p->val = val;
  p->num = 1;
  p->rank = 1;
  return p;
}

Node *initNode(Node *left, Node *right) {
  Node *p = heap.next();
  p->left = left;
  p->right = right;
  return p;
}

bool isLeaf(Node *p) {
  assert(p != nullptr);
  return p->left == nullptr and p->right == nullptr;
}

Node *update(Node *p) {
  if (p == nullptr)
    return nullptr;
  if (isLeaf(p))
    return p;
  p->min = (1 << 30);
  p->num = 0;
  p->rank = 1;
  if (p->left != nullptr) {
    p->min = std::min(p->min, p->left->min);
    p->num += p->left->num;
    p->rank = std::max(p->rank, p->left->rank + 1);
  }
  if (p->right != nullptr) {
    p->min = std::min(p->min, p->right->min);
    p->num += p->right->num;
    p->rank = std::max(p->rank, p->right->rank + 1);
  }
  return p;
}

Node *rotate(Node *v, int d) {
  // fprintf(stderr, "rotate : %d\\n", d);
  assert(not isLeaf(v));
  if (d < 0) {
    Node *w = v->right;
    if (isLeaf(w))
      return v;
    if (w == nullptr)
      return v;
    Node *a = w->left;
    v->right = a;
    w->left = v;
    update(v);
    update(w);
    return w;
  }
  if (d > 0) {
    Node *w = v->left;
    if (isLeaf(w))
      return v;
    if (w == nullptr)
      return v;
    Node *a = w->right;
    v->left = a;
    w->right = v;
    update(v);
    update(w);
    return w;
  }
  assert(0);
}

inline int getRank(Node *p) {
  if (p == nullptr)
    return 0;
  return p->rank;
}

Node *merge(Node *a, Node *b, int d) {
  if (a == nullptr and b == nullptr)
    return nullptr;
  if (a == nullptr or b == nullptr)
    return a == nullptr ? b : a;
  int rL = getRank(a);
  int rR = getRank(b);
  if (rL == rR) {
    Node *p = initNode(a, b);
    return update(p);
  }
  assert(a != nullptr and b != nullptr);
  Node *v, *w;
  if (rL < rR) {
    v = b;
    w = merge(a, b->left, -1);
    v->left = w;
  } else {
    v = a;
    w = merge(a->right, b, 1);
    v->right = w;
  }
  assert(v->left != nullptr and v->right != nullptr);
  int rD = getRank(v->right) - getRank(v->left);
  if (rD < -1)
    v = rotate(v, 1);
  else if (1 < rD)
    v = rotate(v, -1);
  else if (rD < 0 and 0 < d)
    v = rotate(v, 1);
  else if (0 < rD and d < 0)
    v = rotate(v, -1);
  return update(v);
}

std::tuple<Node *, Node *> split(Node *p, int n) {
  if (p == nullptr)
    return std::make_tuple(nullptr, nullptr);
  if (isLeaf(p)) {
    if (n == 0)
      return std::make_tuple(nullptr, p);
    else
      return std::make_tuple(p, nullptr);
  }
  assert(p->left != nullptr and p->right != nullptr);
  int m = p->left->num;
  if (n <= m) {
    auto t = split(p->left, n);
    return std::make_pair(std::get<0>(t), merge(std::get<1>(t), p->right, 0));
  } else {
    auto t = split(p->right, n - p->left->num);
    return std::make_pair(merge(p->left, std::get<0>(t), 0), std::get<1>(t));
  }
}

// [l, r)
int minimum(Node *p, int l, int r) {
  // fprintf(stderr, "(l, r) = (%d, %d)\\n", l, r);
  if (p == nullptr)
    return (1 << 30);
  assert(p != nullptr);
  assert(r <= p->num);
  if (isLeaf(p))
    return p->min;
  if (l == 0 and r == p->num)
    return p->min;
  assert(p->left != nullptr and p->right != nullptr);
  int m = p->left->num;
  if (r <= m)
    return minimum(p->left, l, r);
  if (m <= l)
    return minimum(p->right, l - m, r - m);
  assert(l < m and m < r);
  return std::min(minimum(p->left, l, m), minimum(p->right, m - m, r - m));
}

Node *updateVal(Node *p, int k, int v) {
  if (isLeaf(p) and k == 0) {
    p->min = p->val = v;
    p->num = 1;
    return p;
  }
  assert(not(isLeaf(p) and k != 0));
  int m = p->left == nullptr ? 0 : p->left->num;
  if (k < m) {
    p->left = updateVal(p->left, k, v);
    return update(p);
  } else {
    p->right = updateVal(p->right, k - m, v);
    return update(p);
  }
}

int main() {

  Node *root = nullptr;

  int n;
  scanf("%d", &n);
  int q;
  scanf("%d", &q);
  for (int i = 0; i < n; ++i) {
    int a;
    scanf("%d", &a);
    root = merge(root, initNode(a), 1);
    dumpLine(root);
  }
  dumpLine(root);
  for (int i = 0; i < q; ++i) {
    int x, y, z;
    scanf("%d %d %d", &x, &y, &z);
    if (x == 0) {
      Node *n1, *n2, *n3, *n4;
      std::tie(n1, n2) = split(root, y);
      dumpLine(n1);
      std::tie(n2, n3) = split(n2, z - y);
      dumpLine(n2);
      std::tie(n3, n4) = split(n3, 1);
      dumpLine(n3);
      dumpLine(n4);
      root = merge(merge(merge(n1, n3, 1), n2, 1), n4, 1);
    }
    if (x == 1) {
      int res = minimum(root, y, z + 1);
      printf("%d\\n", res);
    }
    if (x == 2) {
      root = updateVal(root, y, z);
    }
    dumpLine(root);
  }

  return 0;
}

Error: WA

Fixed submission:

#include <bits/stdc++.h>

class Node {
public:
  Node() : left(nullptr), right(nullptr) {}
  int val;
  int min;
  int num;
  int rank;
  Node *left, *right;
};

void dump(Node *p) {
  if (p == nullptr) {
    fprintf(stderr, "(nil)");
    return;
  }
  if (p->left == nullptr and p->right == nullptr) {
    fprintf(stderr, "{n%d}(%d)", p->num, p->val);
    return;
  }
  fprintf(stderr, "{n%d,r%d,m%d}[", p->num, p->rank, p->min);
  dump(p->left);
  fprintf(stderr, ",");
  dump(p->right);
  fprintf(stderr, "]");
}

void dumpLine(Node *p) {
  // return;
  dump(p);
  puts("");
}

template <typename T, int chunksize = 262144> class Heap {
public:
  Heap() : n(chunksize) {}
  std::vector<T *> ptrs;
  std::stack<T *> stack;
  int n;
  T *next() {
    if (not stack.empty()) {
      T *res = stack.top();
      stack.pop();
      return res;
    }
    if (n == chunksize) {
      T *p = new T[chunksize];
      ptrs.push_back(p);
      n = 0;
    }
    T *res = &ptrs[ptrs.size() - 1][n];
    n += 1;
    return res;
  }
  void push(T *p) { stack.push(p); }
};
Heap<Node> heap;

Node *initNode(int val) {
  Node *p = heap.next();
  p->left = p->right = nullptr;
  p->min = p->val = val;
  p->num = 1;
  p->rank = 1;
  return p;
}

Node *initNode(Node *left, Node *right) {
  Node *p = heap.next();
  p->left = left;
  p->right = right;
  return p;
}

bool isLeaf(Node *p) {
  assert(p != nullptr);
  return p->left == nullptr and p->right == nullptr;
}

Node *update(Node *p) {
  if (p == nullptr)
    return nullptr;
  if (isLeaf(p))
    return p;
  p->min = (1 << 30);
  p->num = 0;
  p->rank = 1;
  if (p->left != nullptr) {
    p->min = std::min(p->min, p->left->min);
    p->num += p->left->num;
    p->rank = std::max(p->rank, p->left->rank + 1);
  }
  if (p->right != nullptr) {
    p->min = std::min(p->min, p->right->min);
    p->num += p->right->num;
    p->rank = std::max(p->rank, p->right->rank + 1);
  }
  return p;
}

Node *rotate(Node *v, int d) {
  // fprintf(stderr, "rotate : %d\\n", d);
  assert(not isLeaf(v));
  if (d < 0) {
    Node *w = v->right;
    if (isLeaf(w))
      return v;
    if (w == nullptr)
      return v;
    Node *a = w->left;
    v->right = a;
    w->left = v;
    update(v);
    update(w);
    return w;
  }
  if (d > 0) {
    Node *w = v->left;
    if (isLeaf(w))
      return v;
    if (w == nullptr)
      return v;
    Node *a = w->right;
    v->left = a;
    w->right = v;
    update(v);
    update(w);
    return w;
  }
  assert(0);
}

inline int getRank(Node *p) {
  if (p == nullptr)
    return 0;
  return p->rank;
}

Node *merge(Node *a, Node *b, int d) {
  if (a == nullptr and b == nullptr)
    return nullptr;
  if (a == nullptr or b == nullptr)
    return a == nullptr ? b : a;
  int rL = getRank(a);
  int rR = getRank(b);
  if (rL == rR) {
    Node *p = initNode(a, b);
    return update(p);
  }
  assert(a != nullptr and b != nullptr);
  Node *v, *w;
  if (rL < rR) {
    v = b;
    w = merge(a, b->left, -1);
    v->left = w;
  } else {
    v = a;
    w = merge(a->right, b, 1);
    v->right = w;
  }
  assert(v->left != nullptr and v->right != nullptr);
  int rD = getRank(v->right) - getRank(v->left);
  if (rD < -1)
    v = rotate(v, 1);
  else if (1 < rD)
    v = rotate(v, -1);
  else if (rD < 0 and 0 < d)
    v = rotate(v, 1);
  else if (0 < rD and d < 0)
    v = rotate(v, -1);
  return update(v);
}

std::tuple<Node *, Node *> split(Node *p, int n) {
  if (p == nullptr)
    return std::make_tuple(nullptr, nullptr);
  if (isLeaf(p)) {
    if (n == 0)
      return std::make_tuple(nullptr, p);
    else
      return std::make_tuple(p, nullptr);
  }
  assert(p->left != nullptr and p->right != nullptr);
  int m = p->left->num;
  if (n <= m) {
    auto t = split(p->left, n);
    return std::make_pair(std::get<0>(t), merge(std::get<1>(t), p->right, 0));
  } else {
    auto t = split(p->right, n - p->left->num);
    return std::make_pair(merge(p->left, std::get<0>(t), 0), std::get<1>(t));
  }
}

// [l, r)
int minimum(Node *p, int l, int r) {
  // fprintf(stderr, "(l, r) = (%d, %d)\\n", l, r);
  if (p == nullptr)
    return (1 << 30);
  assert(p != nullptr);
  assert(r <= p->num);
  if (isLeaf(p))
    return p->min;
  if (l == 0 and r == p->num)
    return p->min;
  assert(p->left != nullptr and p->right != nullptr);
  int m = p->left->num;
  if (r <= m)
    return minimum(p->left, l, r);
  if (m <= l)
    return minimum(p->right, l - m, r - m);
  assert(l < m and m < r);
  return std::min(minimum(p->left, l, m), minimum(p->right, m - m, r - m));
}

Node *updateVal(Node *p, int k, int v) {
  if (isLeaf(p) and k == 0) {
    p->min = p->val = v;
    p->num = 1;
    return p;
  }
  assert(not(isLeaf(p) and k != 0));
  int m = p->left == nullptr ? 0 : p->left->num;
  if (k < m) {
    return update(updateVal(p->left, k, v));
  } else {
    return update(updateVal(p->right, k - m, v));
  }
}

int main() {

  Node *root = nullptr;

  int n;
  scanf("%d", &n);
  int q;
  scanf("%d", &q);
  for (int i = 0; i < n; ++i) {
    int a;
    scanf("%d", &a);
    root = merge(root, initNode(a), 1);
    dumpLine(root);
  }
  dumpLine(root);
  for (int i = 0; i < q; ++i) {
    int x, y, z;
    scanf("%d %d %d", &x, &y, &z);
    if (x == 0) {
      Node *n1, *n2, *n3, *n4;
      std::tie(n1, n2) = split(root, y);
      dumpLine(n1);
      std::tie(n2, n3) = split(n2, z - y);
      dumpLine(n2);
      std::tie(n3, n4) = split(n3, 1);
      dumpLine(n3);
      dumpLine(n4);
      root = merge(merge(merge(n1, n3, 1), n2, 1), n4, 1);
    }
    if (x == 1) {
      int res = minimum(root, y, z + 1);
      printf("%d\\n", res);
    }
    if (x == 2) {
      updateVal(root, y, z);
    }
    dumpLine(root);
  }

  return 0;
}