Submission #666455

#	Time	Username	Problem	Language	Result	Execution time	Memory
666455		MilosMilutinovic	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	1543 ms	111124 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 n, d, t;
int a[N];
int add[4 * N];
int mx[4 * N];
int idx[4 * N];
pair<int, int> mn[4 * N];
int prv[N];

void 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]);
}

void 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);
  if (mx[x + 1] >= mx[z]) {
    mx[x] = mx[x + 1];
    idx[x] = idx[x + 1];
  } else {
    mx[x] = mx[z];
    idx[x] = idx[z];
  }
}

pair<int, int> Query(int x, int l, int r, int ll, int rr) {
  if (ll <= l && r <= rr) {
    return mn[x];
  }
  int y = (l + r) >> 1;
  int z = x + 2 * (y - l + 1);
  if (rr <= y) {
    return Query(x + 1, l, y, ll, rr);      
  } else if (ll > y) {
    return Query(z, y + 1, r, ll, rr);
  } else {
    return min(Query(x + 1, l, y, ll, rr), Query(z, y + 1, r, ll, rr));
  }
}

void 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 main() {
  n = readint();
  d = readint();
  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);
  }
  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);
      } 
    }  
  }
  while (d--) {
    int i = idx[0];
    ans -= mx[0];
    while (true) {
      pair<int, int> 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: 20 / 20