LeetCode 088 Merge Sorted Array

题：
https://leetcode.com/problems/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 class Solution {
public void merge(int A[], int m, int B[], int n) {
if (A == null || B == null || A.length == 0 || B.length == 0 || A.length <  m+n) {
return;
}
int a = m - 1;
int b = n - 1;
for (int i=m+n-1; i>=0; i--) {
if (a >=0 && b >= 0) {
if (A[a] > B[b]) {
A[i] = A[a--];
} else {
A[i] = B[b--];
}
} else if (a < 0) {
// only left B
System.arraycopy(B, 0, A, 0, i+1);
} // else {
// only left A, do nothing
//}
}
}
}

往事不堪回首，当初某游戏公司的面试尽然倒在这题上，哎。。。说多了都是泪