Submission #666435

#	Time	Username	Problem	Language	Result	Execution time	Memory
666435		MilosMilutinovic	The short shank; Redemption (BOI21_prison)	C++14	80 / 100	2051 ms	111240 KiB

prison

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

using namespace std;

int readint() {
  char c = getchar();
  while (c < '0' || c > '9') {
    c = getchar();
  }
  int x = 0;
  while (c >= '0' && c <= '9') {
    x = x * 10 + (c - '0');
    c = getchar();
  }
  return x;
}

const int N = 2000005;

int a[N];
int add[4 * N];
int mx[4 * N];
int idx[4 * N];
pair<int, int> mn[4 * N];
int prv[N];

int main() {
  int n = readint();
  int d = readint();
  int t = readint();   
  for (int i = 0; i < n; i++) {
    a[i] = readint();
  }
  vector<int> stk;
  for (int i = 0; i < n; i++) {
    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);
  }
  function<void(int, int, int)> Build = [&](int x, int l, int r) {
    idx[x] = l;
    if (l == r) {
      mn[x] = make_pair(prv[l] == -1 ? n + 1 : prv[l], l);
      return;
    }
    int y = (l + r) >> 1;
    int z = x + 2 * (y - l + 1);
    Build(x + 1, l, y);
    Build(z, y + 1, r);
    mn[x] = min(mn[x + 1], mn[z]);
  };
  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 > rr || r < ll) {
      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);
  function<pair<int, int>(int, int, int, int, int)> Query = [&](int x, int l, int r, int ll, int rr) {
    if (ll <= l && r <= rr) {
      return mn[x];
    }
    if (l > rr || r < ll) {
      return make_pair(n + 2, -1);
    }
    int y = (l + r) >> 1;
    int z = x + 2 * (y - l + 1);
    return min(Query(x + 1, l, y, ll, rr), Query(z, y + 1, r, ll, rr));
  };
  function<void(int, int, int, int)> Remove = [&](int x, int l, int r, int i) {
    if (l == r) {
      mn[x] = make_pair(n + 1, l);
      return;
    }
    int y = (l + r) >> 1;
    int z = x + 2 * (y - l + 1);
    if (i <= y) {
      Remove(x + 1, l, y, i);
    } else {
      Remove(z, y + 1, r, i);
    }
    mn[x] = min(mn[x + 1], mn[z]);
  };
  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);
      } 
    }  
  }
  while (d--) {
    int i = idx[0];
    ans -= mx[0];
    assert(mx[0] >= 0);
    Modify(0, 0, n - 1, i, i, -1e9);
    while (i < n - 1) {
      auto p = Query(0, 0, n - 1, i + 1, n - 1);
      if (p.first <= i) {
        Modify(0, 0, n - 1, p.first, p.second - 1, -1);
        Remove(0, 0, n - 1, p.second);
      } else {
        break;
      }                      
    }
  }
  printf("%d", ans);
  return 0;
}

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