字符串两次翻转

// test.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "iostream"

using namespace std;
void reverse(char * ps, char * pn);
char * strprocess(char * str);
char * strCopy(char * dst, const char * src);

int main(int argc, char * argv[])
{
	char str[] = "could you tell me how to complete this problem";
	char * p = strprocess(str);
	cout<<p<<endl;

	char * p2 = (char *)malloc(strlen(str));
	p2 = strCopy(p2, str);
	cout<<p2<<endl;

	system("pause");
	return 0;
}

char * strprocess(char * str)
{
	if(str == NULL || *str == '\0')
		return NULL;

	char * ps = str;
	char * pn = str;
	while(*pn != '\0') pn++;
	pn--;
	
	reverse(ps, pn);
	ps = str;
	
	while(*ps != '\0')
	{
		pn = ps;
		while(*pn != '\0' && *pn != ' ' ) pn++;
		reverse(ps, pn - 1);
		if(*pn == '\0') break;
		ps = pn + 1;
	}

	return str;
}

void reverse(char * ps, char * pn)
{
	while(ps <= pn)
	{
		char temp = *ps;
		*ps = *pn;
		*pn = temp;
		ps++;
		pn--;
	}
}

// copy str
char * strCopy(char * dst, const char * src)
{
	if(dst == NULL || src == NULL) return NULL;
	char * strDest = dst;
	while((*dst++ = *src++)!='\0');
	return strDest;
}