[leetcode]Merge Sorted Array

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.

算法思路：

剑指offer上面的原题，新数组从后往前生成。

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