Submission #693376

#	Time	Username	Problem	Language	Result	Execution time	Memory
693376		bdl	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	385 ms	55728 KiB

Main

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <array>
#include <iostream>
#include <set>
#include <vector>
using namespace std;

#define ar array

const int N = 1e5, N_ = 1 << 17, L = 17;

ar<int, 2> operator+(const ar<int, 2>& u, const ar<int, 2>& v) {
  return {min(u[0], v[0]), max(u[1], v[1])};
}

int n_;

void build(ar<int, 2> *t, ar<int, 2> *p, int n) {
  for (int i = 0; i < n_; i++)
    t[n_ + i] = i < n ? p[i] : ar{0, 0};
  for (int i = n_ - 1; i > 0; i--)
    t[i] = t[i << 1 | 0] + t[i << 1 | 1];
}

ar<int, 2> query(ar<int, 2> *t, int l, int r) {
  ar<int, 2> x = {N, 0};
  for (l += n_, r += n_; l <= r; l >>= 1, r >>= 1) {
    if ((l & 1) == 1)
      x = x + t[l++];
    if ((r & 1) == 0)
      x = x + t[r--];
  }
  return x;
}

int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  int m;
  scanf("%d", &m);
  static vector<pair<int, int>> el[N + 1], er[N + 1];
  while (m--) {
    int i, j;
    scanf("%d%d", &i, &j), i--, j--;
    if (i < j) {
      er[i].push_back({j, +1});
      er[min(i + k, j)].push_back({j, -1});
    } else {
      el[max(i - k, j) + 1].push_back({j, +1});
      el[i + 1].push_back({j, -1});
    }
  }
  multiset<int> ls, rs;
  static ar<int, 2> p[N];
  for (int i = 0; i < n; i++) {
    for (auto [x, t] : el[i])
      if (t == +1)
        ls.insert(x);
      else
        ls.erase(ls.find(x));
    for (auto [x, t] : er[i])
      if (t == +1)
        rs.insert(x);
      else
        rs.erase(rs.find(x));
    p[i][0] = ls.empty() ? i : *ls.begin();
    p[i][1] = rs.empty() ? i : *rs.rbegin();
  }
  n_ = 1;
  while (n_ < n)
    n_ <<= 1;
  static ar<int, 2> tb[L][N_ * 2];
  build(tb[0], p, n);
  for (int l = 1; l < L; l++) {
    for (int i = 0; i < n; i++)
      p[i] = query(tb[l - 1], p[i][0], p[i][1]);
    build(tb[l], p, n);
  }
  int q;
  scanf("%d", &q);
  while (q--) {
    int i, j;
    scanf("%d%d", &i, &j), i--, j--;
    if (i == j) {
      printf("0\n");
      continue;
    }
    int x = 1;
    ar<int, 2> p = {i, i};
    for (int l = L - 1; l >= 0; l--) {
      ar<int, 2> q = query(tb[l], p[0], p[1]);
      if (q[0] > j || q[1] < j)
        p = q, x += 1 << l;
    }
    printf("%d\n", x == (1 << L) ? -1 : x);
  }
  return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:40:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |   scanf("%d%d", &n, &k);
      |   ~~~~~^~~~~~~~~~~~~~~~
Main.cpp:42:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |   scanf("%d", &m);
      |   ~~~~~^~~~~~~~~~
Main.cpp:46:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |     scanf("%d%d", &i, &j), i--, j--;
      |     ~~~~~^~~~~~~~~~~~~~~~
Main.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |   scanf("%d", &q);
      |   ~~~~~^~~~~~~~~~
Main.cpp:85:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |     scanf("%d%d", &i, &j), i--, j--;
      |     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 11 / 11
• Subtask 4: 25 / 25
• Subtask 5: 35 / 35
• Subtask 6: 13 / 13