C Programming Code Examples
C > Strings Code Examples
C Program to Check if a String is a Palindrome without using the Built-in Function
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/* C Program to Check if a String is a Palindrome without using the Built-in Function
- Take a string as input and store it in the array string[].
- Store the same string into the another array reverse_string[] in the reverse fashion.
- Using for loop compare the elements of both the arrays.
- If all the elements of the array are same, then it is a palindrome. Otherwise it is not a palindrome. */
#include <stdio.h>
#include <string.h>
void main()
{
char string[25], reverse_string[25] = {'\0'};
int j, length = 0, flag = 0;
printf("Enter a string \n");
gets(string);
/* keep going through each character of the string till its end */
for (j = 0; string[j] != '\0'; j++)
{
length++;
}
printf("The length of the string '%s' = %d\n", string, length);
for (j = length - 1; j >= 0 ; j--)
{
reverse_string[length - j - 1] = string[j];
}
/* Check if the string is a Palindrome */
for (flag = 1, j = 0; j < length ; j++)
{
if (reverse_string[j] != string[j])
flag = 0;
}
if (flag == 1)
printf ("%s is a palindrome \n", string);
else
printf("%s is not a palindrome \n", string);
}
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