一道面试题

反转句子的单词顺序！

for example:

this is a apple 

to :

apple a is this

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

//将单个单词的字母顺序反转
void ReverseWords(char* x,char* y)
{
	char t = *x;
	while(x < y)
	{
		t = *x;
		*x = *y;
		x++;
		*y = t;
		y--;
	}
}

char* ReverseSentence(char* Sentence)
{
	char* p = Sentence; // p 指向句子的首个字母
	char* q = p;	    // q 指向句子的空格或'\0'
	while (*q != '\0')
	{
		if (*q == ' ')  // p 指向句子首个字母 q 指向单词的最后一个字母
		{
			// 比如：p -> this is a apple 
			//	 q-1 -> s is a apple
			ReverseWords(p,q-1); 
			// 结果：p -> siht is a apple
			q++;
			p = q;
		}
		else
			q++;
	}
	ReverseWords(p,q-1);         // 反转最后一个单词
	ReverseWords(Sentence,q-1);  // 反转整个句子
	return Sentence;
}

void main()
{
	char Sentence[] = "this is a apple";
	char* Res = ReverseSentence(Sentence);
	printf("%s",Res);
}