Submission #900302

#	Time	Username	Problem	Language	Result	Execution time	Memory
900302		NeroZein	The short shank; Redemption (BOI21_prison)	C++17	100 / 100	1831 ms	97300 KiB

prison

#pragma GCC optimize("Ofast,fast-math,unroll-loops")
#pragma GCC target("avx2,fma")
#include "bits/stdc++.h"
using namespace std;

#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif

const int N = 2e6 + 6;

int a[N];
int ct[N];
int low[N];
int lz[N * 2];
int slow[N * 2];
pair<int, int> seg[N * 2];

inline int merge(int lx, int rx) {
  return low[lx] < low[rx] ? lx : rx;
}

void lowupd(int nd, int l, int r, int p, int v) {
  if (l == r) {
    slow[nd] = l;
    return;
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  if (p <= mid) {
    lowupd(nd + 1, l, mid, p, v); 
  } else {
    lowupd(rs, mid + 1, r, p, v); 
  }
  slow[nd] = merge(slow[nd + 1], slow[rs]); 
}

int lowget(int nd, int l, int r, int s, int e) {
  if (l >= s && r <= e) {
    return slow[nd];
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  if (mid >= e) {
    return lowget(nd + 1, l, mid, s, e);
  } else {
    if (mid < s) {
      return lowget(rs, mid + 1, r, s, e); 
    } else {
      return merge(lowget(nd + 1, l, mid, s, e), lowget(rs, mid + 1, r, s, e)); 
    }
  }
}

inline void push(int nd, int l, int r) {
  if (!lz[nd]) return;
  seg[nd].first += lz[nd];
  if (l != r) {
    int mid = (l + r) >> 1;
    int rs = nd + ((mid - l + 1) << 1);
    lz[nd + 1] += lz[nd];
    lz[rs] += lz[nd]; 
  }
  lz[nd] = 0;
}

void build(int nd, int l, int r) {
  seg[nd] = {0, l};
  if (l == r) {
    return;
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  build(nd + 1, l, mid);
  build(rs, mid + 1, r); 
}

void upd(int nd, int l, int r, int s, int e, int v) {
  push(nd, l, r); 
  if (l >= s && r <= e) {
    lz[nd] = v;
    push(nd, l, r);
    return; 
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  if (mid >= e) {
    push(rs, mid + 1, r); 
    upd(nd + 1, l, mid, s, e, v); 
  } else {
    if (mid < s) {
      push(nd + 1, l, mid); 
      upd(rs, mid + 1, r, s, e, v); 
    } else {
      upd(nd + 1, l, mid, s, e, v); 
      upd(rs, mid + 1, r, s, e, v); 
    }
  }
  seg[nd] = max(seg[nd + 1], seg[rs]); 
}

pair<int, int> get(int nd, int l, int r, int s, int e) {
  push(nd, l, r); 
  if (l >= s && r <= e) {
    return seg[nd];
  }
  int mid = (l + r) >> 1;
  int rs = nd + ((mid - l + 1) << 1);
  if (mid >= e) {
    return get(nd + 1, l, mid, s, e);
  } else {
    if (mid < s) {
      return get(rs, mid + 1, r, s, e); 
    } else {
      return max(get(nd + 1, l, mid, s, e), get(rs, mid + 1, r, s, e)); 
    }
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, d, t;
  cin >> n >> d >> t;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
  }
  build(0, 1, n);
  stack<int> stk;
  low[0] = n + 1; 
  for (int i = 1; i <= n; ++i) {
    stk.push(i);
    while (!stk.empty() && a[stk.top()] + i - stk.top() > t) {
      stk.pop();
    }
    if (!stk.empty()) {
      low[i] = stk.top(); 
      if (low[i] < i) {
        upd(0, 1, n, low[i] + 1, i, 1);        
      }
    } else {
      low[i] = n + 1; 
    }
    lowupd(0, 1, n, i, low[i]);
  }
  for (int iter = 1; iter <= d; ++iter) {
    int mx = get(0, 1, n, 1, n).second;
    while (true) {
      int ind = lowget(0, 1, n, mx, n);
      if (low[ind] >= mx) {
        break;
      }
      upd(0, 1, n, low[ind] + 1, ind, -1);
      low[ind] = n + 1; 
      lowupd(0, 1, n, ind, n + 1); 
    }
  }
  int ans = 0;
  for (int i = 1; i <= n; ++i) {
    if (low[i] <= n) {
      ans++;
    }
  }
  cout << ans << '\n';
  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