两个已排序数组的归并

Cracking the coding interview 9.1

You are given two sorted arrays, A and B, and A has a large enough buffer at the end to hold B. Write a method to merge B into A in sorted order.

思路：从后向前归并。这里有个问题需要注意一下，两个数组的内存区域不能有重叠的部分，否则在归并的过程中会出错。所以在函数入口处做了这个检查。

void MergeArray(int *parrA, int nlengthA, int *parrB, int nlengthB){assert((parrB > parrA + nlengthA + nlengthB - 1) ||   (parrA > parrB + nlengthB - 1)); // make sure no overlap on ArrA and ArrBint *pA = parrA + nlengthA - 1;int *pB = parrB + nlengthB - 1;int *pOut = parrA + nlengthA + nlengthB - 1;while (pA >= parrA && pB >= parrB){if(*pA > *pB){*pOut = *pA;pA--;}else{*pOut = *pB;pB--;}pOut--;}while (pB >= parrB){*pOut = *pB;pB--;pOut--;}}