Question

In C language, please use at least one user defined function, and show data validity check for != integers

3) Write a program to find whether a given number is a Palindrome number (number that is same when you read from forward or backward). You need to take a long integer number from user as input and verify whether it's a number and positive or not. If the input is not valid (e.g., string or float) or positive, then notify the user and ask to input valid positive number again. If the number is valid then check whether it's a palindrome number or not. Input: Key in a number to check: -23 Output: The number -23 is not valid Key in a number to check: 123454321 The number 123454321 is a PALINDROME Do you want to continue (y/n)? y Key in a number to check: 456734 The number 456734 is NOT a PALINDROME Do you want to continue (y/n)? n Good bye!!

Answer 1

#include <stdio.h>

// main function definition
int main()
{
// To store number and reverse
long int num, temp, reverse;
// To store user choice to continue
char choice;

// Loops till user choice is not 'n' or 'N'
do
{
// Loops till valid number entered by the user
do
{
// Accepts a number
printf("\n Key in a number to check: ");
scanf("%d", &num);

// Checks if the number is less than or equals to 0 then display error message
// asks the number to re enter
if(num <= 0)
printf("\n The number %d is not valid.", num);

// Otherwise valid number come out of the loop
else
break;
}while(1);// End of do - while loop

// Stores the number in temp
temp = num;

// Re sets the reverse to 0 for every number
reverse = 0;

// Loops till temp number not equals to 0
// to calculate reverse
while (temp != 0)
{
// Calculates the reverse by multiplying the reverse number with 10
// and adds the remainder of the number
reverse = reverse * 10 + temp % 10;
// Calculates the quotient
temp /= 10;
}// End of while loop

// Checks if the original number is equals to reverse number then palindrome
if (num == reverse)
printf("%d is a palindrome number.\n", num);

// Otherwise the original number is not equals to reverse number then not palindrome
else
printf("%d not a palindrome number.\n", num);

// Clears the console
fflush(stdin);
// Accepts user choice to continue
printf("\n Do you want to continue(y/n)? ");
scanf("%c", &choice);

// Checks if user choice is 'N' or 'n' then come out of the loop
if(choice == 'N' || choice == 'n')
break;
}while(1);// End of do - while loop
printf("\n Good bye!!");
return 0;
}// End of main function

Sample Output:

Key in a number to check: -23

The number -23 is not valid.
Key in a number to check: 123454321
123454321 is a palindrome number.

Do you want to continue(y/n)? y

Key in a number to check: 456734
456734 not a palindrome number.

Do you want to continue(y/n)? n

Good bye!!