C Program to Check if a given String is Palindrome

1. #include <stdio.h>

2. #include <string.h>

4. void main()

5. {

6.     char string[25], reverse_string[25] = {'\0'};

7.     int  i, length = 0, flag = 0;

9.     fflush(stdin);

10.     printf("Enter a string \n");

11.     gets(string);

12.     /*  keep going through each character of the string till its end */

13.     for (i = 0; string[i] != '\0'; i++)

14.     {

15.         length++;

16.     }

17.     for (i = length - 1; i >= 0; i--)

18.     {

19.        reverse_string[length - i - 1] = string[i];

20.     }

21.     /*

22.      * Compare the input string and its reverse. If both are equal

23.      * then the input string is palindrome.

24.      */

25.     for (i = 0; i < length; i++)

26.     {

27.         if (reverse_string[i] == string[i])

28.             flag = 1;

29.         else

30.             flag = 0;

31.     }

32.     if (flag == 1)

33.         printf("%s is a palindrome \n", string);

34.     else

35.         printf("%s is not a palindrome \n", string);

36. }