归并排序（C++模版技术实现）

下面代码仅供本人复习数据结构所用，实用性N低，各位飘过吧~~哈哈:>

//
// C++ 模版技术实现归并排序. 
// 

#include <cstdlib>
#include <cstring> 
#include <iostream>
#include <stdexcept>

//
// 归并操作. 
//
template <typename T> 
void merge(T *array, const size_t low, const size_t mid, const size_t high)
{	
	if (NULL == array) {
		throw std::invalid_argument("参数 array 为 NULL.");
	}
	
	// 辅组空间. 
	T *tempArray = new T[high - low + 1];
	
	size_t i, begin1, begin2;
	for (i = 0, begin1 = low, begin2 = mid + 1; 
		begin1 <= mid && begin2 <= high; ++i)
	{
		tempArray[i] = array[begin1] < array[begin2] 
			? array[begin1++] : array[begin2++];
	}

	while (begin1 <= mid) {
		tempArray[i++] = array[begin1++];
	} 
	while (begin2 <= high) {
		tempArray[i++] = array[begin2++];
	}
	
	for (i = 0; i < high - low + 1; ++i) {
		array[low + i] = tempArray[i];
	}
	
	delete[] tempArray;
}

//
// 归并排序. 
//
template <typename T>
void mergeSort(T *array, const size_t first, const size_t last)
{
	if (first < last)
	{
		size_t mid = (first + last) / 2;
		mergeSort(array, first, mid);
		mergeSort(array, mid + 1, last);
		merge(array, first, mid, last);
	}
}

//
// 测试 
//
int main(void)
{
	char szTest[] = "Merge sort algorithm test case !"; 
	int iarrTest[] = {23, 12, 2, 123, 72, 35, 49, 51, 83, 94, 65}; 
	const size_t INT_ARR_SIZE = sizeof(iarrTest) / sizeof(iarrTest[0]);

	mergeSort(szTest, 0, strlen(szTest) - 1);
	mergeSort(iarrTest, 0, INT_ARR_SIZE - 1);

	std::cout << szTest << std::endl;

	for (size_t i = 0; i < INT_ARR_SIZE; ++i)
	{
		std::cout << iarrTest[i] << " "; 
	}
	std::cout << std::endl;

	return EXIT_SUCCESS; 
}