泛型算法_快速排序源码

好久没写这些底层算法了，趁这个周末有空，顺便实现了下。程序里的指针是否为空都没有判断，毕竟这些玩意都是追求速度的嘛！

如有不当之处请指出，欢迎讨论！

下面的程序在VS2008下测试通过，以下是运行结果：

1.头文件 myalgorithm.h

#ifndef _MYALGORITHM_H_13551534
#define _MYALGORITHM_H_13551534

typedef bool (*FuncCompare)(void *p1, void *p2);
typedef void (*FuncUser)(void *p);
void ForEach(void *begin, void *end, int nTypeSize, FuncUser func);
void* PreProcess(void *begin, void *end, int nTypeSize, FuncCompare func);
void Qsort(void *begin, void *end, int nTypeSize, FuncCompare func);

#endif

2.源文件 myalgorithm.cpp

#include "myalgorithm.h"
#include "string.h"
void ForEach(void *begin, void *end, int nTypeSize, FuncUser func)
{
  char *p = (char*)begin;
  while (p != end)
  {
    func(p);
    p += nTypeSize;
  }
}

void* PreProcess(void *begin, void *end, int nTypeSize, FuncCompare func)
{
  char* i = (char*)begin;
  char* j = (char*)end;
  j -= nTypeSize;

  char* pivot = new char[nTypeSize];
  memcpy(pivot, begin, nTypeSize);

  while(i < j)
  {
    while(i < j && func(pivot, j)) j -= nTypeSize;
    if (i < j) 
    {
      memcpy(i, j, nTypeSize); i += nTypeSize;
    }
    while(i < j && func(i, pivot)) i += nTypeSize;
    if (i < j) 
    {
      memcpy(j, i, nTypeSize); j -= nTypeSize;
    }
  }
  memcpy(i, pivot, nTypeSize);
  delete pivot;
  pivot = NULL;
  return i;
}


void Qsort(void *begin, void *end, int nTypeSize, FuncCompare func)
{
  if (begin != end)
  {
    char *pivot = (char*)PreProcess(begin, end, nTypeSize, func);
    Qsort(begin, pivot, nTypeSize, func);
    Qsort(pivot + nTypeSize, end, nTypeSize, func);
  }
}

3. 客户端实现qsort.cpp

#include "stdio.h"
#include "stdlib.h"
#include "myalgorithm.h"

typedef struct _PERSON 
{
  int nID;
  char *szName;
}PERSON;

bool CompareInt(void *p1, void *p2)
{
  int a = *(int*)p1;
  int b = *(int*)p2;
  return a < b;
}

bool CompareStr(void *p1, void *p2)
{
  char *c1 = *(char**)p1;
  char *c2 = *(char**)p2;
  
  while (*c1!= '\0' && *c2!= '\0')
  {
    if (*c1 > *c2)
    {
      return false;
    }
    else if (*c1 < *c2)
    {
      return true;
    }
    ++c1;
    ++c2;
  }
  return true;
}

bool ComparePersonById(void *p1, void *p2)
{
  PERSON *person1 = (PERSON*)p1;
  PERSON *person2 = (PERSON*)p2;
  return person1->nID < person2->nID;
}

bool ComparePersonByName(void *p1, void *p2)
{
  PERSON *person1 = (PERSON*)p1;
  PERSON *person2 = (PERSON*)p2;
  return CompareStr(&person1->szName, &person2->szName);
}
void PrintInt(void *p)
{
  int a = *(int*)p;
  printf("%d ", a);
}
void PrintStr(void *p)
{
  char **str = (char**)p;
  printf("%s ", *str);
}
void PrintPersonInfo(void *p)
{
  PERSON *person = (PERSON*)p;
  printf("ID: %d  Name: %s\n", person->nID, person->szName);
}
int _tmain(int argc, _TCHAR* argv[])
{

  //整型数组排序
  printf("************整型数组排序************\n");
  int arr[] = {5, 1, 3, 6, 2, 1, 9, 7, 3, 0};
  printf("原始数据：\n");
  ForEach(arr, arr + 10, 4, PrintInt);
  printf("\n");
  Qsort(arr, arr+10, 4, CompareInt);
  printf("排序后：\n");
  ForEach(arr, arr + 10, 4, PrintInt);
  printf("\n\n");


  //字符串排序
  printf("************字符串排序************\n");
  printf("原始数据：\n");
  char* szName[] = {"jack", "liufeng", "zhangsan", "aniu", "wangqiang", "hanmei"};
  ForEach(szName, szName+6, 4, PrintStr);
  printf("\n");
  Qsort(szName, szName+6, 4, CompareStr);
  printf("排序后：\n");
  ForEach(szName, szName+6, 4, PrintStr);
  printf("\n\n");

  //结构体排序
  PERSON person[6] = {34, "zhangsan", 23, "lisi", 53, "hamei", 12, "zhangqiang", 67, "huyong", 45, "qianqian"};

  // 1. 按ID排序

  printf("************结构体排序************\n");
  printf("原始数据：\n");
  ForEach(person, person + 6, sizeof(PERSON), PrintPersonInfo);
  printf("\n按ID排序：\n");
  Qsort(person, person + 6, sizeof(PERSON), ComparePersonById);
  ForEach(person, person + 6, sizeof(PERSON), PrintPersonInfo);
  printf("\n");

  // 2. 按名称排序
  printf("\n按名称排序：\n");
  Qsort(person, person + 6, sizeof(PERSON), ComparePersonByName);
  ForEach(person, person + 6, sizeof(PERSON), PrintPersonInfo);
  printf("\n");

  system("pause");
  return 0;
}