Submission #659395

#	Time	Username	Problem	Language	Result	Execution time	Memory
659395		600Mihnea	The short shank; Redemption (BOI21_prison)	C++17	80 / 100	2015 ms	150396 KiB

prison

#include <bits/stdc++.h>

using namespace std;

const int N = 2000000 + 7;
const int INF = (int) 1e9 + 7;
int n;
int d;
int t;
int trebel[N];
bool block[N];
int ant[N];
bool valid[N];
set<int> valids;

pair<int, int> tree_min_valid[4 * N];

void st_valid(int v, int tl, int tr, int i, int x) {
  if (tr < i || i < tl) {
    return;
  }
  if (tl == tr) {
    assert(tl == i);
    assert(tr == i);
    tree_min_valid[v] = {x, i};
    return;
  }
  int tm = (tl + tr) / 2;
  st_valid(2 * v, tl, tm, i, x);
  st_valid(2 * v + 1, tm + 1, tr, i, x);
  tree_min_valid[v] = min(tree_min_valid[2 * v], tree_min_valid[2 * v + 1]);
}

pair<int, int> get_min_valid(int v, int tl, int tr, int l, int r) {
  if (tr < l || r < tl) {
    return {INF, -1};
  }
  if (l <= tl && tr <= r) {
    return tree_min_valid[v];
  }
  int tm = (tl + tr) / 2;
  return min(get_min_valid(2 * v, tl, tm, l, r), get_min_valid(2 * v + 1, tm + 1, tr, l, r));
}

pair<int, int> tree[4 * N];
int lazy[4 * N];

void push(int v, int tl, int tr) {
  if (lazy[v]) {
    tree[v].first += lazy[v];
    if (tl < tr) {
      lazy[2 * v] += lazy[v];
      lazy[2 * v + 1] += lazy[v];
    }
    lazy[v] = 0;
  }
}

void add(int v, int tl, int tr, int l, int r, int x) {
  push(v, tl, tr);
  if (tr < l || r < tl) {
    return;
  }
  if (l <= tl && tr <= r) {
    lazy[v] += x;
    push(v, tl, tr);
    return;
  }
  int tm = (tl + tr) / 2;
  add(2 * v, tl, tm, l, r, x);
  add(2 * v + 1, tm + 1, tr, l, r, x);
  tree[v] = max(tree[2 * v], tree[2 * v + 1]);
}

void build(int v, int tl, int tr) {
  if (tl == tr) {
    tree[v] = {0, tl};
  } else {
    int tm = (tl + tr) / 2;
    build(2 * v, tl, tm);
    build(2 * v + 1, tm + 1, tr);
    tree[v] = max(tree[2 * v], tree[2 * v + 1]);
  }
}

int main() {
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

///  freopen ("input.txt", "r", stdin);

  for (int i = 0; i < 4 * N; i++) {
    tree_min_valid[i] = {INF, -1};
  }

  cin >> n >> d >> t;
  for (int i = 1; i <= n; i++) {
    cin >> trebel[i];
  }
  build(1, 1, n - 1);
  vector<int> stk;
  for (int i = 1; i <= n; i++) {
    while (!stk.empty() && trebel[stk.back()] - stk.back() >= trebel[i] - i) {
      stk.pop_back();
    }
    stk.push_back(i);
    int L = 0, R = (int) stk.size() - 1;
    while (L <= R) {
      int mid = (L + R) / 2;
      int j = stk[mid];
      if (trebel[j] + i - j <= t) {
        ant[i] = j;
        L = mid + 1;
      } else {
        R = mid - 1;
      }
    }
  }
  for (int i = 1; i <= n; i++) {
    valid[i] = (ant[i] > 0);
    if (valid[i]) {
      st_valid(1, 1, n, i, ant[i]);
    }
  }
  for (int j = 1; j <= n; j++) {
    if (valid[j]) {
      add(1, 1, n - 1, ant[j], j, +1);
    }
  }

  for (int iqd = 1; iqd <= d; iqd++) {
    push(1, 1, n - 1);
    int jj = tree[1].second;
    assert(1 <= jj && jj < n);
    assert(!block[jj]);
    add(1, 1, n - 1, jj, jj, -(int) 1e9);
    block[jj] = 1;
    while (1) {
      auto it = get_min_valid(1, 1, n, jj + 1, n);
      int j = it.second;
      if (it.first <= jj) {
        assert(it.first == ant[j]);
        valid[j] = 0;
        if (ant[j] <= j - 1) {
          add(1, 1, n - 1, ant[j], j - 1, -1);
        }
        st_valid(1, 1, n, j, INF);
      } else {
        break;
      }
    }
  }
  int sol = 0;
  for (int i = 1; i <= n; i++) {
    sol += valid[i];
  }
  cout << sol << "\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: 0 / 20