We have been given two sorted arrays and a number K . We have to merge the two sorted arrays in the sorted manner and return the element at the Kth position.

• My approach is to use two variables which will tell us where are we in the two arrays.
• Start comparing arr1[arr1_index] with arr2[arr2_index] and see who is smaller.
• Now , Start a loop with the smaller element and move forward to see if there are other elements following the smaller element which are smaller than the greater of the two values , we just compared in the previous step.
• Write those values in a new array and following them write the greater value in that array too.
• If we come across duplicates then doubly write them one after the other.

I have done it myself and am wondering if there is an more efficient approach to it, and if you know then please describe it in a beginner-friendly language.

It contains a lot of console output statements, thought that it would ease the reviewers :)

public class TwoSortedArraysKthElement {
    static int KthElementInTwoArrays(int[] arr1,int arr1_length, int[] arr2, int arr2_length,int k){
        int[] new_arr = new int[arr1_length+arr2_length];
        int lastIndexOfNewArr = -1;
        int arr1_loop_index = 0;
        int arr2_loop_index = 0;
        while (arr1_loop_index < arr1_length && arr2_loop_index < arr2_length) {
            for (int i : new_arr) {
                System.out.print(i+" ");
            }
            System.out.println();
            System.out.println("LastIndex is "+ lastIndexOfNewArr);
            if (arr1[arr1_loop_index] < arr2[arr2_loop_index]) {
                int greater_val = arr2[arr2_loop_index];
                for (int i = arr1_loop_index; i < arr1_length; i++) {
                    if (arr1[i] <= greater_val) {
                        new_arr[lastIndexOfNewArr + 1] = arr1[i];
                        lastIndexOfNewArr++;
                        arr1_loop_index++;
                        System.out.println("LastIndex is "+ lastIndexOfNewArr);
                        System.out.println("arr1Index is "+ arr1_loop_index);
                    } else {
                        break;
                    }
                }
                new_arr[lastIndexOfNewArr+1] = greater_val;
                lastIndexOfNewArr++;
                arr2_loop_index++;
                for (int i : new_arr) {
                    System.out.print(i+" ");
                }
                System.out.println();
                System.out.println("LastIndex is "+ lastIndexOfNewArr);
                System.out.println("arr2Index is "+ arr2_loop_index);
            } else if (arr1[arr1_loop_index] > arr2[arr2_loop_index]) {
                int greater_val = arr1[arr1_loop_index];
                for (int i = arr2_loop_index; i < arr2_length; i++) {
                    if (arr2[i] <= greater_val) {
                        new_arr[lastIndexOfNewArr + 1] = arr2[i];
                        lastIndexOfNewArr++;
                        arr2_loop_index++;
                        System.out.println("LastIndex is "+ lastIndexOfNewArr);
                        System.out.println("arr2Index is "+ arr2_loop_index);
                    } else {
                        break;
                    }
                }
                new_arr[lastIndexOfNewArr+1] = greater_val;
                lastIndexOfNewArr++;
                arr1_loop_index++;
                for (int i : new_arr) {
                    System.out.print(i+" ");
                }
                System.out.println();
                System.out.println("LastIndex is "+ lastIndexOfNewArr);
                System.out.println("arr1Index is "+ arr1_loop_index);
            } else {
                new_arr[lastIndexOfNewArr+1] = arr1[arr1_loop_index];
                arr1_loop_index++;
                lastIndexOfNewArr++;
                System.out.println("lastindex is "+ lastIndexOfNewArr);
                System.out.println("arr1index is "+ arr1_loop_index);
                new_arr[lastIndexOfNewArr+1] = arr2[arr2_loop_index];
                arr2_loop_index++;
                lastIndexOfNewArr++;
                System.out.println("lastindex is "+ lastIndexOfNewArr);
                System.out.println("arr2index is "+ arr2_loop_index);

            }
            for (int i : new_arr) {
                System.out.print(i+" ");
            }
            System.out.println();
        }
        if (arr1_loop_index >= arr1_length) {
            for (int i = arr2_loop_index; i < arr2_length;i++) {
                new_arr[lastIndexOfNewArr+1] = arr2[i];
                lastIndexOfNewArr++;
            }
        } else if (arr2_loop_index >= arr2_length) {
            for (int i = arr1_loop_index; i < arr1_length;i++) {
                new_arr[lastIndexOfNewArr+1] = arr1[i];
                lastIndexOfNewArr++;
            }
        }
        for (int i : new_arr) {
            System.out.print(i+" ");
        }
        System.out.println();

        return new_arr[k+1];
    }
    public static void main(String[] args) {
        int[] arr1 = {1,2,3,5,6};
        int[] arr2 = {4,5,6,7,8};
        int k = 5;
        System.out.println("the element at the kth position is "+KthElementInTwoArrays(arr1,arr1.length,arr2,arr2.length,k));
    }
}