Apartments

input/code.cpp: In function 'int main()':
input/code.cpp:23:3: error: 'sort' was not declared in this scope; did you mean 'short'?
   23 |   sort(b + 1, b + m + 1);
      |   ^~~~
      |   short

#include <iostream>
#include <set>

using namespace std;

const int N = 2e5 + 5;

int n, m, k;
int a[N], b[N];
multiset<int> mts;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m >> k;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    mts.insert(a[i]);
  }
  for (int i = 1; i <= m; i++) {
    cin >> b[i];
  }
  sort(b + 1, b + m + 1);
  int ans = 0;
  for (int i = 1; i <= m; i++) {
    if (mts.lower_bound(b[i] - k) == mts.end()) {
      continue;
    }
    int x = *mts.lower_bound(b[i] - k);
    if (x <= b[i] + k) {
      ans++;
      mts.erase(mts.find(x));
    }
  }
  cout << ans << '\n';
  return 0;
}