Merge Two Sorted Arrays

/*
 * Problem : Merge sorted arrays.
 * Input   : Two counts and two arrays.
 * Output  : The merged array.
 * Approach: Two pointers.
 * Time    : O(n + m)
 * Space   : O(n + m)
 * Java    : 8 or newer.
 */
import java.util.Scanner;
import java.util.Arrays;
import java.util.stream.Collectors;

public class Main {
    // This method solves the task. It receives the input and returns the answer.
    static int[] solve(int[] a, int[] b) {
        int[] result = new int[a.length + b.length];
        int i = 0;
        int j = 0;
        int k = 0;

        // Step 1: Compare the front elements of both arrays and take the smaller one.
        while (i < a.length && j < b.length) {
            if (a[i] <= b[j]) {
                result[k++] = a[i++];
            } else {
                result[k++] = b[j++];
            }
        }

        // Step 2: One array is finished. Copy the rest of the other array.
        while (i < a.length) {
            result[k++] = a[i++];
        }
        while (j < b.length) {
            result[k++] = b[j++];
        }
        return result;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int size = scanner.nextInt();
        int[] a = new int[size];
        for (int i = 0; i < size; i++) {
            a[i] = scanner.nextInt();
        }
        int sizeB = scanner.nextInt();
        int[] b = new int[sizeB];
        for (int i = 0; i < sizeB; i++) {
            b[i] = scanner.nextInt();
        }
        System.out.println(Arrays.stream(solve(a, b)).mapToObj(String::valueOf).collect(Collectors.joining(" ")));
    }
}