1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 void exchange(char *string, int c1, int c2);
 5 void revertString(char *string, int iStart, int iEnd);
 6 void revertWordsInString(char *string);
 7 
 8 int main(int argc, const char * argv[])
 9 {
10 
11     // insert code here...
12     printf("Begin>>>!\n");
13     
14     char originalString[100] = "abcdef";
15     printf("%s\n", originalString);
16     size_t len = strlen(originalString);
17     revertString(originalString, 0, (int)(len-1));
18     printf("%s\n", originalString);
19     
20     char string[100] = "I am a student coming from XX";
21     printf("%s\n", string);
22     revertWordsInString(string);
23     printf("%s\n", string);
24     
25     
26     return 0;
27 }
28 
29 void revertString(char *string, int iStart, int iEnd)
30 {
31     while (iStart < iEnd) {
32         exchange(string, iStart, iEnd);
33         iStart++;
34         iEnd--;
35     }
36 }
37 
38 void exchange(char *string, int c1, int c2)
39 {
40     char tmp = string[c1];
41     string[c1] = string[c2];
42     string[c2] = tmp;
43 }
44 
45 void revertWordsInString(char *string)
46 {
47     size_t len = strlen(string);
48     int indexEnd = (int)len - 1;
49     int i = 0;
50     int j = 0;
51     while (j < indexEnd) {
52         while (*(string + j) != ‘ ‘) {
53             j++;
54             if (j >= indexEnd) {
55                 break;
56             }
57         }
58         if (j < indexEnd) {
59             revertString(string, i, j-1);
60             j++;
61             i = j;
62         }
63     }
64     revertString(string, i, j);
65     revertString(string, 0, indexEnd);
66 }