Leetcode: 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.

这种题都采用倒序的方式吧，从大到小添加。要注意的是一些小细节：比如for(int i = m+n-1; i >=0; i--){}, 在for语句里面已经有i--了，循环里面就不需要再写一个i--了

public class Solution {
    public void merge(int A[], int m, int B[], int n) {
        int j = m - 1, k = n - 1;
        for (int i = m+n-1; i >= 0; i--) {
            if (j >= 0 && k >= 0){
                if (A[j] >= B[k]) {
                    A[i] = A[j];
                    j--;
                }
                else {
                    A[i] = B[k];
                    k--;
                }
            }
            else if (k >= 0) {
                A[i] = B[k];
                k--;
            }
        }
    }
}