01 #include <stdio.h>
02 
03 int anagram(char [], char []);
04 
05 int main()
06 {
07     char str1[50], str2[50];
08     int check;
09 
10     printf("Enter first string : ");
11     gets(str1);
12 
13     printf("Enter second string : ");
14     gets(str2);
15     check = anagram(str1, str2);
16 
17     if (check == 1)
18         printf(""%s" and "%s" are Anagrams.", str1, str2);
19     else
20         printf(""%s" and "%s" are not Anagrams.", str1, str2);
21 
22 }
23 
24 int anagram(char s1[], char s2[])
25 {
26     int first_str[256] = {0}; // initialized by 0
27     int second_str[256] = {0};
28     /*
29     first_str and second_str are used for counting character occurrence.
30     size 256 >> (possible character symbols).
31     */
32 
33     int i = 0;
34 
35     while (s1[i] != '')
36     {
37         first_str[s1[i]]++;  //increament occurrence count
38         i++;
39     }
40 
41     i = 0;
42 
43     while (s2[i] != '')
44     {
45         second_str[s2[i]]++; //increament occurrence count
46         i++;
47     }
48 
49     for (i = 0; i < 256; i++)
50     {
51         if (first_str[i] != second_str[i])
52             return 0;
53     }
54     return 1;
55 }

 OUTPUT :
 
 1st RUN:
 
 Enter first string : cola
 Enter second string : coal
 
 "cola" and "coal" are Anagrams.
 
 
 2nd RUN:
 
 Enter first string : hey
 Enter second string : yah
 
 "hey" and "yah" are not Anagrams.