简单mem族函数的实现

#include "stdafx.h"
#include <stdio.h>
#include <string.h>

void * Memset(void *dest , char c ,size_t count)
{
	char *p = (char*)dest;
	size_t i = 0;
	while(i < count)
	{	
		*p = c;
		++p;	
		++i;
	}
	return dest;
}

void * Memcpy(void *dest , void *src , size_t count)
{
	char *pd = (char*)dest;
	char *ps = (char*)src;
	size_t i = 0;
	while(i<count)
	{
		*pd = *ps;
		++pd,++ps;
		++i;
	}
	return dest;
}
int MemCmp(void *s1 , void *s2 , size_t count)
{
	char *p1 = (char *)s1;char *p2 = (char *)s2;

	while(*p1 == *p2 && --count)
	{
		++p1;++p2;
	}
	if(*p1 > *p2)
		return 1;
	else if (*p1 < *p2)
		return -1;
	else
		return 0;
}
int main(int argc, char* argv[])
{
	int i = -1;
	int j = 1;
	//memset(&i,0,sizeof(int));
	Memcpy(&i,&j,sizeof(int));
	int a[3] = {-1,1,255};
	int b[3] ;
	Memset(b,0,sizeof(b));
	Memcpy(b,a,sizeof(b));
	char s1[] = "abcd123";
	char s2[] = "bccd234";
	int nRes = MemCmp(s1,s2,1);
	if (nRes > 0)
		puts("前面大");
	else if(nRes < 0)
		puts("后面大");
	else
		puts("一样大");
	return 0;
}
#include "stdafx.h"
#include <stdio.h>
#include