剑指Offer41 反转单词顺序，单词字符顺序不变

 /*************************************************************************
     > File Name: 41_ReverseWords.c
     > Author: Juntaran
     > Mail: JuntaranMail@gmail.com
     > Created Time: 2016年09月04日 星期日 16时18分34秒
  ************************************************************************/

 #include <stdio.h>

 // 反转单词
 void ReverseWord(char* left, char* right)
 {
     if (left== NULL || right==NULL)
         return;
     while (left < right)
     {
         char temp = *left;
         *left = *right;
         *right = temp;

         left ++;
         right --;
     }
 }

 void Reverse(char* str)
 {
     if (str == NULL)
         return;

     char* left = str;
     char* right = str;
     while (*(right+) != '\0')
         right++;

     // 先反转整个句子
     ReverseWord(left, right);

     // 再逐步反转每个单词
     left = str;
     right = str;
     while (*left != '\0')
     {
         if (*left == ' ')
         {
             left ++;
             right++;
         }
         else if (*right==' ' || *right=='\0')
         {
             ReverseWord(left, --right);
             left = ++right;
         }
         else
         {
             right ++;
         }
     }
 }

 int main()
 {
     char str[] = "I am a student. ";
     Reverse(str);

     printf("%s\n", str);
     return ;
 }