字符串翻转，单词内不翻转

字符串翻转，单词内不翻转。如I am from Chongqing->Chongqing from am I
 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<string.h>
 4 
 5 void reverse(char *str, int beg, int end);
 6 void reverseSentece(char *str);
 7 int main()
 8 {
 9     char str[128];
10     gets_s(str,128);
11     reverseSentece(str);
12     puts(str);
13     system("pause");
14     return 0;
15 }
16 
17 void reverse(char *str, int beg, int end)
18 {
19     char temp;
20     if(str == NULL)
21         return;
22     while(beg <= end)
23     {
24         temp = str[beg];
25         str[beg] = str[end];
26         str[end] = temp;
27         beg++;
28         end--;
29     }
30 }
31 
32 void reverseSentece(char *str)
33 {
34     int beg = 0;
35     int end = 0;
36     if(str == NULL)
37         return;
38     //翻转整个句子
39     reverse(str,0,strlen(str)-1);
40     //局部翻转
41     while(str[end] != '')
42     {
43         //找到单词的结束
44         while(str[end] != '' && str[end] != ' ')
45             ++end;
46         //翻转一个单词
47         reverse(str,beg,end-1);
48         if(str[end] == '')
49             break;
50         ++end;
51         beg = end;
52     }
53 }