Example: Palindrome Numbers in Range (String Conversion) in C

// Palindrome Numbers in Range (String Conversion)
#include <stdio.h>
#include <string.h> // For strlen
#include <stdlib.h> // For sprintf

// Function to check if a number is a palindrome using string conversion
int isPalindromeString(int n) {
    char str[20]; // Buffer to hold the string representation of the number
    
    // Handle negative numbers
    if (n < 0) {
        return 0;
    }

    // Convert integer to string
    sprintf(str, "%d", n);

    int length = strlen(str);
    int i = 0;             // Pointer from the start
    int j = length - 1;    // Pointer from the end

    // Compare characters from both ends towards the middle
    while (i < j) {
        if (str[i] != str[j]) {
            return 0; // Not a palindrome
        }
        i++;
        j--;
    }

    return 1; // It is a palindrome
}

int main() {
    int start_range, end_range;

    // Step 1: Get user input for the range
    printf("Enter the starting number of the range: ");
    scanf("%d", &start_range);
    printf("Enter the ending number of the range: ");
    scanf("%d", &end_range);

    // Step 2: Ensure valid range
    if (start_range > end_range) {
        int temp = start_range;
        start_range = end_range;
        end_range = temp;
    }

    // Step 3: Print header for results
    printf("Palindrome numbers in the range %d to %d are:\n", start_range, end_range);

    // Step 4: Iterate through the range and check each number
    for (int i = start_range; i <= end_range; i++) {
        if (isPalindromeString(i)) {
            printf("%d ", i);
        }
    }
    printf("\n");

    return 0;
}