C++ program for Palindrome number using For Loop

Before going to the program first let us understand what is a Palindrome Number?

Palindrome Number:

It is a number which remains same even when the number is reversed.

For example,

Numbers like 0,1,2,11,44,121,222,242,345543 are called as Palindrome Numbers.

Program code to find whether a Number is Palindrome or Not:

#include<iostream.h>
#include<conio.h>
void main()
{ int i,n,r,s=0; clrscr(); cout<<"n Enter The Number:"; cin>>n; for(i=n;i>0; ) { r=i%10; s=s*10+r; i=i/10; } /* CHECKING IF THE NUMBER ENTERED AND THE REVERSE NUMBER IS EQUAL OR NOT */ if(s==n) { cout<<n<<" is a Palindrome Number"; } else { cout<<n<<" is a not Palindrome Number"; } getch();
}

Related: C program for Palindrome number using For Loop

Working:

First the computer reads the number to find the reverse of the number.
Then using for loop the reverse number is calculated.
Then finally the reverse number is compared with the entered number and if they are equal then it is printed as “(Given number) is a palindrome number ” else it is printed as “(Given number) is not a palindrome number “.

Step by Step working of the above Program Code:

Let us assume that the number entered by the user is 121.

It assigns the value of s=0,n=121.
Then it assigns the value of i=n (i=121) in the initialization part of the for loop.
Then the loop continues till the condition of the for loop is true.

3.1. i>0 (121>0) for loop condition is true

r=i%10 (r=121%10) So r=1

s=s*10+r (s=0*10+1) So s=1

i=i/10 (i=121/10) So i=12

3.2. i>0 (12>0) for loop condition is true

r=i%10 (r=12%10) So r=2

s=s*10+r (s=1*10+2) So s=12

i=i/10 (i=12/10) So i=1

3.3. i>0 (1>0) for loop condition is true

r=i%10 (r=1%10) So r=1

s=s*10+r (s=12*10+1) So s=121

i=i/10 (i=1/10) So i=0