Java: Merge elements of A with B by maintaining the sorted order

Last update on April 01 2025 10:37:39 (UTC/GMT +8 hours)

Given two sorted arrays A and B of size p and q, write a Java program to merge elements of A with B by maintaining the sorted order i.e. fill A with first p smallest elements and fill B with remaining elements.

Example:
Input :
int[] A = { 1, 5, 6, 7, 8, 10 }
int[] B = { 2, 4, 9 }
Output:
Sorted Arrays:
A: [1, 2, 4, 5, 6, 7]
B: [8, 9, 10]

Sample Solution:

Java Code:

// Import necessary Java classes.
import java.util.Arrays;

// Define a class named 'solution'.
class solution
{
    // A method to merge two sorted arrays.
    public static void merge_sorted_arrays(int[] A, int p, int[] B, int q)
    {
        // Loop through the first array.
        for (int i = 0; i < p; i++)
        {
            if (A[i] > B[0])
            {
                // Swap elements if the current element in A is greater than the first element in B.
                int temp = A[i];
                A[i] = B[0];
                B[0] = temp;

                // Store the first element from B.
                int first_arr = B[0];
                int k;

                // Move elements in B to the right to insert first_arr in the correct position.
                for (k = 1; k < q && B[k] < first_arr; k++) {
                    B[k - 1] = B[k];
                }

                // Insert first_arr in the correct position in B.
                B[k - 1] = first_arr;
            }
        }
    }

    public static void main (String[] args)
    {
        int[] A = { 1, 5, 6, 7, 8, 10 };
        int[] B = { 2, 4, 9 };
        int p = A.length;
        int q = B.length;

        // Print the original arrays.
        System.out.println("Original Arrays:");
        System.out.println("A: " + Arrays.toString(A));
        System.out.println("B: " + Arrays.toString(B));

        // Merge the sorted arrays A and B.
        merge_sorted_arrays(A, p, B, q);

        // Print the sorted arrays A and B after merging.
        System.out.println("\nSorted Arrays:");
        System.out.println("A: " + Arrays.toString(A));
        System.out.println("B: " + Arrays.toString(B));
    }
}

Sample Output:

Original Arrays:
A: [1, 5, 6, 7, 8, 10]
B: [2, 4, 9]

Sorted Arrays:
A: [1, 2, 4, 5, 6, 7]
B: [8, 9, 10]

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to merge two sorted arrays into a third sorted array without using extra space.
• Write a Java program to merge three sorted arrays into a single sorted array.
• Write a Java program to merge two unsorted arrays and sort the final array in O(n log n) time.
• Write a Java program to find the intersection of two sorted arrays.

Java Code Editor:

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