Apartments

#include <iostream>
#include <vector>
#include <algorithm>

int main() {
    
    int n, m, k; // applicants, apartments, max allowed difference
    std::cin >> n >> m >> k;
    
    std::vector<int> desired_app_size;
    std::vector<int> app_size;

    for (int i = 0; i < n; i++) {
        int a;
        std::cin >> a;
        desired_app_size.push_back(a);
    }

    for (int i = 0; i < m; i++) {
        int m;
        std::cin >> m;
        app_size.push_back(m);
    }

    // sort both vectors
    sort(desired_app_size.begin(), desired_app_size.end());
    sort(app_size.begin(), app_size.end());

    // greedy approach
    int count = 0;
    int apartment_ptr = 0;
    int applicant_ptr = 0;

    while (apartment_ptr < m && applicant_ptr < n) {
        // 1. apartment fits
        if (abs(desired_app_size.at(applicant_ptr) - app_size.at(apartment_ptr)) <= k) {
            count++;
            apartment_ptr++;
            applicant_ptr++;
        } 
        // 2. apartment to small
        else if (app_size.at(apartment_ptr) < desired_app_size.at(applicant_ptr)) {
            apartment_ptr++;
        }
        // 3. applicant doesn't fit
        else {
            applicant_ptr++;
        }
    }

    std::cout << count;


    // std::cout << "Desired app sizes: " << std::endl;
    // for (auto a : desired_app_size) {
    //     std::cout << a << " ";
    // }
    // std::cout << std::endl << "App sizes: " << std::endl;
    // for (auto a : app_size) {
    //     std::cout << a << " ";
    // }
    // std::cout << std::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