Question 5 Rocky Bhai Solution

import java.util.*;
public class Rocky {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int numTests = sc.nextInt();
        for (int testNumber = 0; testNumber < numTests; testNumber++) {
            int m = sc.nextInt();
            int n = sc.nextInt();
            int k = sc.nextInt();
            int[] t = new int[m];
            int[] p = new int[m];
            for (int i = 0; i < m; i++)
                t[i] = sc.nextInt();
            for (int i = 0; i < m; i++)
                p[i] = sc.nextInt();
            int l = 0;
            int r = t[0] + (k - 1) * p[0];
            int[] q = new int[m];
            while (l < r) {
                int mm = (l + r) / 2;
                for (int i = 0; i < m; i++) {
                    if (mm < t[i])
                        q[i] = 0;
                    else
                        q[i] = (mm - t[i]) / p[i] + 1;
                }
                Arrays.sort(q);
                long cur = 0;
                for (int i = m - 1; i >= 0 && i >= m - n; i--)
                    cur += q[i];
                if (cur >= k)
                    r = mm;
                else
                    l = mm + 1;
            }
            System.out.println(l);
        }
    }
}