What is a Happy Number?
A Happy Number is a number that will eventually reach 1 when replaced by the sum of the squares of each digit repeatedly. If it loops endlessly in a cycle (other than 1), it’s called an Unhappy Number.
Example:
- Start with
19→
1² + 9² = 1 + 81 = 82
8² + 2² = 64 + 4 = 68
6² + 8² = 36 + 64 = 100
1² + 0² + 0² = 1 → Happy Number!
📌 Steps to Check a Happy Number in C
- Take input from the user.
- Find sum of squares of each digit.
- Repeat the process until the number becomes
1(Happy) or loops endlessly (Unhappy). - Display result to the user.
#include<stdio.h>
#include<conio.h>
void main(){
int f,n,d,sq,temp,ans=0;
clrscr();
printf("Enter your number ");
scanf("%d",&n);
f=n;
do{
while(n!=0){
d=n%10;
sq=d*d;
ans=ans+sq;
n=n/10;
}
temp=ans;
n=temp;
ans=0;
}while(temp>=9);
if(temp==1){
printf("The number %d is happy number",f);
}
else{
printf("The number %d is not happy number",f);
}
getch();
}
📥 Sample Input and Output
Example 1:
Enter a number: 19
19 is a Happy Number.
Example 2:
Enter a number: 4
4 is not a Happy Number.