Untitled

public class MyClass {
    
    public static int[] joinArrays(int[] arr1, int[] arr2) {
        int[] res = new int[arr1.length+arr2.length];
        for(int i=0; i < arr1.length+arr2.length;i++){
            if (i < arr1.length) {
                res[i] = arr1[i];
            } else {
                res[i] = arr2[i - arr1.length];
            }
        }
        return res;
    }
    
    private static void printArray(String pretext, int[] arr) {
        System.out.println("\n" + pretext);
        for (int element: arr) {
            System.out.print(element + " ");
        }
    }
    
    public static int[] reduceArray(int[] arr, int start, int end, int k, String space){
        System.out.println("\n" + space + "Start = " + start + ", End = " + end);
        if (end <= start) {
            int[] res = { arr[start] };
            return res;
        }
        
        if ((end - start) == 1) {
            int prod = arr[start] * arr[end];
            if (prod < k) {
                int[] res = { prod };
                return res;
            } else {
                int[] res = { arr[start], arr[end] };
                return res;
            }
        } else {
            int len = (end - start) / 2;
            int mid = start + len;
            int[] arr1 = reduceArray(arr, start, mid, k, space + " ");
            int[] arr2 = reduceArray(arr, mid+ 1, end, k, space + " ");
            int[] newArr = joinArrays(arr1, arr2);
            if (newArr.length == ((end-start) + 1)) {
                return newArr;
            } else {
                return reduceArray(newArr, 0, newArr.length-1, k, space + " ");
            }
        }
    }
    
    public static void main(String args[]) {
      int[] arr = {1,2,3,4,5,6,7,8};
      int[] res = reduceArray(arr, 0, 7, 20, "");
      printArray("Result: ", res);
    }
}