solution.cpp

#include <bits/stdc++.h>

using namespace std;

vector<string> split_string(string);

// Implementation Part
string twoArrays(int k, vector<int> A, vector<int> B) {

    // sort A in creasing order
    // sort B in decreasing order
    sort(A.begin(), A.end());
    sort(B.begin(), B.end(), greater<int>());
    
    // check for all i such that
    // A[i] + B[i] < k
    for(int i = 0; i < A.size(); i++){
        if(A[i] + B[i] < k)
            return "NO";
    }
    return "YES";
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    int q;
    cin >> q;
    cin.ignore(numeric_limits<streamsize>::max(), '\n');

    for (int q_itr = 0; q_itr < q; q_itr++) {
        string nk_temp;
        getline(cin, nk_temp);

        vector<string> nk = split_string(nk_temp);

        int n = stoi(nk[0]);

        int k = stoi(nk[1]);

        string A_temp_temp;
        getline(cin, A_temp_temp);

        vector<string> A_temp = split_string(A_temp_temp);

        vector<int> A(n);

        for (int i = 0; i < n; i++) {
            int A_item = stoi(A_temp[i]);

            A[i] = A_item;
        }

        string B_temp_temp;
        getline(cin, B_temp_temp);

        vector<string> B_temp = split_string(B_temp_temp);

        vector<int> B(n);

        for (int i = 0; i < n; i++) {
            int B_item = stoi(B_temp[i]);

            B[i] = B_item;
        }

        string result = twoArrays(k, A, B);

        fout << result << "\n";
    }

    fout.close();

    return 0;
}

vector<string> split_string(string input_string) {
    string::iterator new_end = unique(input_string.begin(), input_string.end(), [] (const char &x, const char &y) {
        return x == y and x == ' ';
    });

    input_string.erase(new_end, input_string.end());

    while (input_string[input_string.length() - 1] == ' ') {
        input_string.pop_back();
    }

    vector<string> splits;
    char delimiter = ' ';

    size_t i = 0;
    size_t pos = input_string.find(delimiter);

    while (pos != string::npos) {
        splits.push_back(input_string.substr(i, pos - i));

        i = pos + 1;
        pos = input_string.find(delimiter, i);
    }

    splits.push_back(input_string.substr(i, min(pos, input_string.length()) - i + 1));

    return splits;
}