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C program to check whether the given number is a palindromic number.

If a number, which when read in both forward and backward way is same, then such a number is called a palindrome number.

Program:

#include
int main()
{
int n, n1, rev = 0, rem;
printf(“Enter any number:
“);
scanf(”%d”, &n);
n1 = n;

/* logic */
while (n > 0)
{
rem = n % 10;
rev = rev * 10 + rem;
n = n / 10;
}

if (n1 == rev)
{
printf(“Given number is a palindromic number”);
}
else
{
printf(“Given number is not a palindromic number”);
}
return 0;
}

Output:
Enter any number: 121
Given number is a palindrome

If a number, which when read in both forward and backward way is same, then such a number is called a palindrome number.

Program:

#include

int main() {

int n, n1, rev = 0, rem;

printf("Enter any number:
");

scanf("%d", &n);

n1 = n;

/* logic */

while (n > 0){

rem = n % 10;

rev = rev * 10 + rem;

n = n / 10;

}

if (n1 == rev){

printf(“Given number is a palindromic number”);

}

else{

printf(“Given number is not a palindromic number”);

}

return 0;

}

Output:

Enter any number: 121

Given number is a palindrome

Explanation with an example:

Consider a number n=121, reverse=0, remainder;

number=121

now the while loop is executed /* the condition (n>0) is satisfied */

/* calculate remainder */

remainder of 121 divided by 10=(121%10)=1;

now reverse=(reverse*10)+remainder

=(010)+1 / we have initialized reverse=0 */

=1

number=number/10

=121/10

=12

now the number is 12, greater than 0. The above process is repeated for number=12.

remainder=12%10=2;

reverse=(1*10)+2=12;

number=12/10=1;

now the number is 1, greater than 0. The above process is repeated for number=1.

remainder=1%10=1;

reverse=(12*10)+1=121;

number=1/10 /* the condition n>0 is not satisfied,control leaves the while loop */

Program stops here. The given number=121 equals the reverse of the number. Thus the given number is a palindrome number.