Example: Palindrome Check by Reversing String in C

// Palindrome Check by Reversing String
#include <stdio.h>
#include <string.h> // Required for strlen(), strcpy(), strcmp()

// Function to check if a string is a palindrome
// Returns 1 if palindrome, 0 otherwise
int isPalindromeReverse(const char *str) {
    // Step 1: Handle null or empty string
    if (str == NULL || strlen(str) == 0) {
        return 1; // Empty string is considered a palindrome
    }

    // Step 2: Get the length of the original string
    int length = strlen(str);

    // Step 3: Create a buffer for the reversed string
    // +1 for the null terminator
    char reversed_str[length + 1];

    // Step 4: Reverse the string
    int i, j;
    for (i = 0, j = length - 1; i < length; i++, j--) {
        reversed_str[i] = str[j];
    }
    reversed_str[length] = '\0'; // Null-terminate the reversed string

    // Step 5: Compare the original string with the reversed string
    // strcmp returns 0 if strings are identical
    if (strcmp(str, reversed_str) == 0) {
        return 1; // Strings are identical, so it's a palindrome
    } else {
        return 0; // Strings are different
    }
}

int main() {
    char str1[] = "madam";
    char str2[] = "racecar";
    char str3[] = "hello";
    char str4[] = ""; // Empty string
    char str5[] = "a"; // Single character string
    char str6[] = "Madam"; // Case sensitive example

    printf("'%s' is a palindrome: %d\n", str1, isPalindromeReverse(str1));
    printf("'%s' is a palindrome: %d\n", str2, isPalindromeReverse(str2));
    printf("'%s' is a palindrome: %d\n", str3, isPalindromeReverse(str3));
    printf("'%s' is a palindrome: %d\n", str4, isPalindromeReverse(str4));
    printf("'%s' is a palindrome: %d\n", str5, isPalindromeReverse(str5));
    printf("'%s' is a palindrome: %d\n", str6, isPalindromeReverse(str6)); // Will be 0 due to case sensitivity

    return 0;
}