Submission #1036329

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036329		ind1v	Count Squares (CEOI19_countsquares)	C++11	100 / 100	364 ms	9260 KiB

countsquares

#include <bits/stdc++.h>

using namespace std;

const int N = 1505;

int h, v;
int y[N], x[N];
vector<int> s;
int cnt[N * N];

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> h >> v;
  s.reserve(h * h);
  for (int i = 1; i <= h; i++) {
    cin >> y[i];
    for (int j = 1; j <= i - 1; j++) {
      s.emplace_back(y[i] - y[j]);
    }
  }
  sort(s.begin(), s.end());
  s.erase(unique(s.begin(), s.end()), s.end());
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= i - 1; j++) {
      cnt[lower_bound(s.begin(), s.end(), y[i] - y[j]) - s.begin()]++;
    }
  }
  long long ans = 0;
  for (int i = 1; i <= v; i++) {
    cin >> x[i];
    for (int j = 1; j <= i - 1; j++) {
      if (binary_search(s.begin(), s.end(), x[i] - x[j])) {
        ans += cnt[lower_bound(s.begin(), s.end(), x[i] - x[j]) - s.begin()];
      }
    }
  }
  cout << ans << '\n';
  return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 40 / 40
• Subtask 3: 53 / 53