Submission #666421

#	Time	Username	Problem	Language	Result	Execution time	Memory
666421		MilosMilutinovic	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	2093 ms	4200 KiB

prison

/**
 *    author:  wxhtzdy
 *    created: 28.11.2022 15:11:47
**/
#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n, d, t;
  cin >> n >> d >> t;
  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  vector<int> prv(n);
  vector<int> stk;
  for (int i = 0; i < n; i++) {
    prv[i] = -1;      
    for (int j = 0; j <= i; j++) {
      if (a[j] + (i - j) <= t) {
        prv[i] = j;        
      }
    }
    /* while (!stk.empty() && a[stk.back()] + i - stk.back() > t) {
      stk.pop_back();
    }
    while (!stk.empty() && a[stk.back()] - stk.back() > a[i] - i) {
      stk.pop_back();
    }      
    prv[i] = (a[i] <= t ? i : (stk.empty() ? -1 : stk.back()));
    stk.push_back(i); */
  }
  vector<int> add(4 * n);
  vector<int> mx(4 * n);
  vector<int> idx(4 * n);
  function<void(int, int, int)> Build = [&](int x, int l, int r) {
    idx[x] = l;
    if (l == r) {
      return;
    }
    int y = (l + r) >> 1;
    int z = x + 2 * (y - l + 1);
    Build(x + 1, l, y);
    Build(z, y + 1, r);
  };
  function<void(int, int, int)> Pull = [&](int x, int y, int z) {
    if (mx[y] > mx[z]) {
      mx[x] = mx[y];
      idx[x] = idx[y];
    } else {
      mx[x] = mx[z];
      idx[x] = idx[z];
    }
  };
  function<void(int, int, int, int, int, int)> Modify = [&](int x, int l, int r, int ll, int rr, int v) {
    if (ll <= l && r <= rr) {
      add[x] += v;
      mx[x] += v;
      return;
    }  
    if (l > ll || r < ll || l > r) {
      return;
    }
    int y = (l + r) >> 1;
    int z = x + 2 * (y - l + 1);
    if (add[x] != 0) {
      mx[x + 1] += add[x];
      mx[z] += add[x];
      add[x + 1] += add[x];
      add[z] += add[x];
      add[x] = 0;
    }
    Modify(x + 1, l, y, ll, rr, v);
    Modify(z, y + 1, r, ll, rr, v);
    Pull(x, x + 1, z);
  };
  Build(0, 0, n - 1);
  int ans = 0;
  for (int i = 0; i < n; i++) {
    if (prv[i] != -1) {
      ans += 1;
      if (prv[i] < i) {
        Modify(0, 0, n - 1, prv[i], i - 1, +1);
      } 
    }  
  }
  vector<bool> rem(n);
  while (d--) {
    int i = idx[0];
    ans -= mx[0];
    Modify(0, 0, n - 1, i, i, -1e9);
    rem[i] = true;
    for (int j = i + 1; j < n; j++) {
      if (prv[j] != -1 && prv[j] <= i) {
        if (prv[j] < j) {
          Modify(0, 0, n - 1, prv[j], j - 1, -1);
        }
        prv[j] = -1;
      }
    }
  }
  cout << ans << '\n';
  return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20