Example: Merge Two Sorted Arrays using Two Pointers in Java

// Merge Two Sorted Arrays using Two Pointers
public class Main {
    public static void main(String[] args) {
        int[] arr1 = {10, 20, 30};
        int[] arr2 = {15, 25, 35, 40};

        int[] mergedArray = mergeSortedArraysTwoPointers(arr1, arr2);

        System.out.print("Merged Array (Two Pointers): ");
        for (int num : mergedArray) {
            System.out.print(num + " ");
        }
        System.out.println();
    }

    public static int[] mergeSortedArraysTwoPointers(int[] arr1, int[] arr2) {
        // Step 1: Calculate the total length of the new array
        int[] mergedArray = new int[arr1.length + arr2.length];

        // Step 2: Initialize pointers for arr1, arr2, and mergedArray
        int i = 0; // Pointer for arr1
        int j = 0; // Pointer for arr2
        int k = 0; // Pointer for mergedArray

        // Step 3: Iterate while both pointers are within their array bounds
        while (i < arr1.length && j < arr2.length) {
            if (arr1[i] <= arr2[j]) {
                mergedArray[k++] = arr1[i++];
            } else {
                mergedArray[k++] = arr2[j++];
            }
        }

        // Step 4: Add remaining elements from arr1 (if any)
        while (i < arr1.length) {
            mergedArray[k++] = arr1[i++];
        }

        // Step 5: Add remaining elements from arr2 (if any)
        while (j < arr2.length) {
            mergedArray[k++] = arr2[j++];
        }

        // Step 6: Return the merged array
        return mergedArray;
    }
}