Merge Sorted Array

MergeSortedArray.java

/*
Given two sorted integer arrays A and B, merge B into A as one sorted array.

Note:
You may assume that A has enough space to hold additional elements from B. The number of elements initialized in A and B are m and n respectively.
*/

public class Solution {
    public void merge(int A[], int m, int B[], int n) {
        int indexInsert = m + n - 1;
        int mm = m - 1;
        int nn = n - 1;
        
        while (mm >= 0 && nn >= 0){
            if (A[mm] > B[nn]){
                A[indexInsert--] = A[mm--];
            }
            else{
                A[indexInsert--] = B[nn--];
            }
        }
        
        while (nn >= 0){
            A[indexInsert--] = B[nn--];
        }
    }
}