[LeetCode] Merge Sorted Array [22]

题目

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 andn respectively.

原题链接（点我）

解题思路

合并两个数组为一个有序数组，这题也很简单，唯一考查的地方就是怎么处理数组，是从前往后还是从后往前。一般情况，从后往前的效率比从前往后高，也要省不少事。代码如下，从后开始合并。

代码实现：

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

[LeetCode] Merge Sorted Array [22],布布扣,bubuko.com

[LeetCode] Merge Sorted Array [22]

原文：http://blog.csdn.net/swagle/article/details/29378433