模板实现排序

// CmpTest.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <string.h>
template <class T, class CMP_FUN>
bool MySort(T* psArray, int i4Num, CMP_FUN CmpFun);

typedef struct __MYTEST__
{
    int a;
    int b;
} S_MYTEST;

//a>b 从小到大
bool Cmp2(S_MYTEST &a, S_MYTEST &b)
{
    return (a.a > b.a);
}

//a>b 从大到小
bool Cmp3(int &a, int &b)
{
    return (a < b);
}


int main(int argc, char* argv[])
{
    int array[10] = {1,2,3,4,6,7,5};
    MySort(array, 10, Cmp3);
    
    S_MYTEST stMyTest[5] = {{1,2},{0,3},{10,9},{11,8},{23,1}};
    MySort(stMyTest, 5, Cmp2);
    
    return 0;
}


//选择排序
template <class T, class CMP_FUN>
bool MySort(T* psArray, int i4Num, CMP_FUN CmpFun)
{
    int i4Count = 1;//次数
    int i4Index = 0; //索引

    T *psSelElement = 0; //记录的元素(最大或者最小)
    T TempElement; //临时变量,用于数据交换
    memset(&TempElement, 0, sizeof(T));
    
    //查找符合条件的元素 保存在 psSelElement
    for (i4Count = 1; i4Count < i4Num; i4Count++)
    {
        psSelElement = &psArray[0]; //初始为第一个元素
        for (i4Index = 1; i4Index <= i4Num - i4Count; i4Index++)
        {
            if (NULL == psSelElement)
            {
                return false;
            }
            if (CmpFun(psArray[i4Index], *psSelElement))
            {
                psSelElement = &psArray[i4Index];//修改为满足要求的元素
            }
        }

        //将psSelElement 替换到 最后的位置(i4Num - i4Count)
        if (psSelElement != &psArray[i4Num - i4Count])
        {
            memcpy(&TempElement, &psArray[i4Num - i4Count], sizeof(T));
            memcpy(&psArray[i4Num - i4Count], psSelElement, sizeof(T));
            if (NULL == psSelElement)
            {
                return false;
            }
            memcpy(psSelElement, &TempElement, sizeof(T));
        }
    }

    return true;
}