Submission #729011

#	Time	Username	Problem	Language	Result	Execution time	Memory
729011		MilosMilutinovic	Advertisement 2 (JOI23_ho_t2)	C++14	100 / 100	717 ms	25028 KiB

Main

/**
 *    author:  wxhtzdy
 *    created: 12.02.2023 12:07:23
**/
#include <bits/stdc++.h>

using namespace std;

const int N = 500500;
const int M = 8 * N;

int st[2][M];

void build(int x, int p, int l, int r, int v) {
  st[x][p] = v;
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  build(x, p * 2, l, mid, v);
  build(x, p * 2 + 1, mid + 1, r, v);
}

int query(int x, int p, int l, int r, int ll, int rr) {
  if (l > r || l > rr || r < ll) {
    return -2e9;
  }
  if (ll <= l && r <= rr) {
    return st[x][p];
  }
  int mid = l + r >> 1;
  return max(query(x, p * 2, l, mid, ll, rr), query(x, p * 2 + 1, mid + 1, r, ll, rr));
}

void modify(int x, int p, int l, int r, int i, int v) {
  st[x][p] = max(st[x][p], v);
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  if (i <= mid) {
    modify(x, p * 2, l, mid, i, v);
  } else {
    modify(x, p * 2 + 1, mid + 1, r, i, v);
  }
}
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n;
  cin >> n;
  vector<int> x(n);
  vector<int> e(n);
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> e[i];
  }
  vector<int> order(n);
  iota(order.begin(), order.end(), 0);
  sort(order.begin(), order.end(), [&](int i, int j) {
    return e[i] > e[j];
  });
  vector<int> xs;
  for (int i = 0; i < n; i++) {
    xs.push_back(x[i]);
  }  
  sort(xs.begin(), xs.end());
  xs.erase(unique(xs.begin(), xs.end()), xs.end());
  int k = (int) xs.size();
  auto GetVal = [&](int t) {
    return (int) (lower_bound(xs.begin(), xs.end(), t) - xs.begin());
  };
  build(0, 1, 0, k - 1, -2e9);
  build(1, 1, 0, k - 1, -2e9);
  int ans = 0;
  for (int i : order) {
    // e[j] - x[j] >= e[i] - x[i], x[i] <= x[j]
    // e[j] + x[j] >= x[i] + e[i], x[i] >= x[j]
    int p = GetVal(x[i]);
    if (query(0, 1, 0, k - 1, p, k - 1) >= e[i] - x[i]) {
      continue;      
    }
    if (query(1, 1, 0, k - 1, 0, p) >= e[i] + x[i]) {
      continue;
    }
    ans += 1;
    modify(0, 1, 0, k - 1, p, e[i] - x[i]);
    modify(1, 1, 0, k - 1, p, e[i] + x[i]);
  }
  cout << ans << '\n';          
  return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void build(int, int, int, int, int)':
Main.cpp:19:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |   int mid = l + r >> 1;
      |             ~~^~~
Main.cpp: In function 'int query(int, int, int, int, int, int)':
Main.cpp:31:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   31 |   int mid = l + r >> 1;
      |             ~~^~~
Main.cpp: In function 'void modify(int, int, int, int, int, int)':
Main.cpp:40:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |   int mid = l + r >> 1;
      |             ~~^~~

• Subtask 1: 10 / 10
• Subtask 2: 23 / 23
• Subtask 3: 36 / 36
• Subtask 4: 31 / 31