LeetCode 88 - Merge Sorted Array

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 (size that is greater or equal to m + n) to hold additional elements from B. The number of elements initialized in A and B are m and n respectively.

public void merge(int A[], int m, int B[], int n) {
    int pos = m+n-1;
    m--; n--;
    while(m>=0 || n>=0) {
        if(m>=0 && (n<0 || A[m] >= B[n])) {
            A[pos--] = A[m--];
        } else {
            A[pos--] = B[n--];
        }
    }
}