Apartments

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

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

  int n, m, k;
  cin >> n >> m >> k;

  vector<int> appl, apart;
  int x;
  for (int i = 0; i < n; i++) {
    cin >> x;
    appl.push_back(x);
  }

  for (int i = 0; i < m; i++) {
    cin >> x;
    apart.push_back(x);
  }

  sort(appl.begin(), appl.end());
  sort(apart.begin(), apart.end());

  auto appl_iter = appl.begin();
  auto apart_iter = apart.begin();
  size_t counter = 0;
  while (apart_iter != apart.end() && appl_iter != appl.end()) {
    if (abs(*appl_iter - *apart_iter) <= k) {
      counter++;
      appl_iter++;
      apart_iter++;
    } else if (*apart_iter > *appl_iter) {
      appl_iter++;
    } else {
      apart_iter++;
    }
  }

  cout << counter << endl;

  return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED