007字符串之一

// 007.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

//全部翻转
bool AllReverse(char *pBegin, char *pEnd);

bool Reverse(char *pBuffer)
{
	if (NULL == pBuffer)
	{
		return false;
	}

	char *pBegin = pBuffer;
	int len =0;
	while(*pBegin != '\0')
	{
		len++;
		pBegin++;
	}
	char *pEnd	 = pBuffer+len-1;
	bool bRet = false;//反转成功与否

	pBegin = pBuffer;
	bRet = AllReverse(pBegin, pEnd);
	if (!bRet)
	{
		return false;
	}

	pBegin = pEnd = pBuffer;
	//以空格为界限翻转每个字符串
	char spaceChar = ' ';

	while (*pBegin != '\0')
	{
		if (*pBegin == spaceChar)
		{
			pBegin++;
			pEnd++;
			continue;
		}
		else if (*pEnd == spaceChar || *pEnd == '\0')
		{
			AllReverse(pBegin, --pEnd);
			pBegin = ++pEnd;//因为之前--pEnd，最终的位置指向了结束符或者空格符前一个字符
		}
		else
		{
			pEnd++;
		}
	}
}


bool AllReverse(char *pBegin, char *pEnd)
{
	if (NULL == pBegin || NULL == pEnd)
	{
		return false;
	}
	//全部翻转
	while(pBegin < pEnd)//不能为!=条件
	{
		char tmp = *pBegin;
		*pBegin = *pEnd;
		*pEnd	= tmp;
		
		pBegin++;
		pEnd--;
	}
	return true;

}

	

//翻转字符串，先总体翻转再单个翻转
int main(int argc, char* argv[])
{
	char pBuffer[] = "I AM A STUDENT.";
	Reverse(pBuffer);
	
	printf("%s", pBuffer);

	return 0;
}