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 to hold additional elements from B. The number of

elements initialized in A and B are m and n respectively.

思路：从后往前操作，可以避免很多操作。

class Solution{public:void merge(int A[],int m,int B[],int n){int ia = m-1,ib = n-1,icur = m+n-1;while(ia >= 0 && ib >= 0){if(A[ia] > B[ib])A[icur--] = A[ia--];elseA[icur--] = B[ib--];}while(ib >= 0)A[icur--] = B[ib--];}};