在c ++中使用自定义类模板，再用merge函数不能用，那怎么重载merge函数呢

在C语言中，merge.c实现的是合并的方法
一、归并排序算法
算法的递推关系：一个大的数列需要排序，把它从中间分成两部分，每一部分归并排序，然后把排好序的这两个部分再合并起来（合并的时候要按顺序合并）。
算法的Base Case：如果分成的这部分只有一个数，那么这个部分就不用再排序（看做已经排好序的）。
实现这个算法用了三个函数，每个函数在一个文件中，分别为：merge.c sort.c 和 main.c，其中merge.c实现的是合并的方法，sort.c实现的是排序的方法，main.c是一个测试实例。还有三个头文件，分别指出了函数原型。

merge.c：
/*This is a merge program.
* Given an integer ARRAY and three numbers which indicate the begain
*and the end of two subarrays, merge the two subarrays to a bigger
*one. The two subarrays are alrealy sorted from small to big.
* For example, given an array a[10] and three numbers 0, 3 and 5. The
*first array is from a[0] to a[2], the seconde array is from a[3] to
*a[4]. The number 3 and 5 are the upper side. This program merge the
*two arrays together.
*
*Author: Eric
*Time: 2011.01.08
*/
#include
#include

#include "main.h"

void merge(int *a, int idxa, int idxb, int idxc)
{
int i = idxa, j = idxb, k = 0;
int total = idxc-idxa;
//int temp[total] = {0};
int *temp = (int *)malloc(sizeof(int) * total);
if(temp == NULL)
{
fprintf(stderr, "malloc error in merge function\n");
return;
}
while(i < idxb && j < idxc)
{
if(a[i] < a[j])
temp[k++] = a[i++];
else
temp[k++] = a[j++];
}

if(i == idxb)
{
while(j < idxc)
temp[k++] = a[j++];
}
else if(j == idxc)
{
while(i < idxb)
temp[k++] = a[i++];
}

/*Copy the temp to the sorce array*/
for(i = 0, k = idxa; i < total; k++, i++)
a[k] = temp[i];

free(temp);
}

#ifndef MAIN
/*For test*/
int main()
{
int a[10];
int i = 0;
int idxa=1, idxb=5, idxc=8;

printf("Please input 10 numbers to the array:");
for(i = 0; i < 10; i++)
scanf("%d", &a[i]);
printf("Three indexes are %d, %d and %d.\nThe first subarray is:", idxa, idxb, idxc);
for(i = idxa; i < idxb; i++)
printf(" %d", a[i]);
printf("\nThe second subarray is:");
for(i = idxb; i < idxc; i++)
printf(" %d", a[i]);
printf("\n");

merge(a, idxa, idxb, idxc);
printf("The merged array is:");
for(i = idxa; i < idxc; i++)
printf(" %d", a[i]);
printf("\n");

return 0;
}
#endif

merge.h：
/*Author: Eric
*Time: 2011.01.08
*/

void merge(int *a, int idxa, int idxb, int idxc);

sort.c:
/*This is a function for sorting an array useing merge.c
*
*Author: Eric
*Time: 2011.01.08
*/
#include

#include "main.h"
#include "merge.h"

/*Sort array a, from a[begin] to a[upend-1]*/
void sort(int *a, int begin, int upend)
{
int n = upend - begin; /*the number to be sorted*/
/*The first array is a[idxa] to a[idxb-1]. The second is a[idxb] to a[idxc-1]*/
int idxa = begin,
idxb = ((begin+upend)%2 == 0) ? (begin+upend)/2 : (begin+upend+1)/2,
idxc = upend;

if(n < 2)
{
printf("The array elements are less than two. No need to sort\n");
return;
}
else if(n == 2)
merge(a, idxa, idxb, idxc);
else
{
if(idxb-idxa > 1)
sort(a, idxa, idxb);
if(idxc-idxb > 1)
sort(a, idxb, idxc);
merge(a, idxa, idxb, idxc);
}
}

#ifndef MAIN
#define MAIN
/*For test*/
int main()
{
int a[10] = {1, 4, 8, 5, 10, 25, 54, 15, 12, 2};
int i = 0;

sort(a, 0, 10);

printf("The sorted array is:");
for(i = 0; i < 10; i++)
printf(" %d", a[i]);
printf("\n");

return 0;
}
#endif