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.

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对于该题，考虑从前往后比较，这样的话免去了大量数据的移动，提高了效率，代码如下：

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