Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:
You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.

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