The Program in C++ Program to check If number is a Happy or not is given below:
#include <iostream>
#include <unordered_set>
using namespace std;
int sumOfSquaredDigits(int n) {
int sum = 0;
while (n > 0) {
int digit = n % 10;
sum += digit * digit;
n /= 10;
}
return sum;
}
bool isHappyNumber(int n) {
unordered_set<int> seen;
while (n != 1) {
n = sumOfSquaredDigits(n);
if (seen.count(n) > 0) {
return false;
}
seen.insert(n);
}
return true;
}
int main() {
int n;
cout << "Hello Codeauri Family,Enter a number here to check if it's a happy number or not!:\n ";
cin >> n;
if (isHappyNumber(n)) {
cout << n << " is a happy number." << endl;
} else {
cout << n << " is not a happy number." << endl;
}
return 0;
}
Output:
Hello Codeauri Family,Enter a number here to check if it’s a happy number or not!:
7
7 is a happy number.
Pro-Tips💡
This program implements a function sumOfSquaredDigits to find the sum of the squares of the digits of a number.
It also implements a function isHappyNumber to check if a number is a happy number.
The isHappyNumber function uses an unordered set to keep track of numbers that have already been seen to avoid getting stuck in an infinite loop.
The main function takes a number from the user and calls the isHappyNumber function to check if it’s a happy number.
If it is, the program prints that the number is a happy number, otherwise it prints that it is not.
Learn C-Sharp ↗
C-sharp covers every topic to learn about C-Sharp thoroughly.
Learn C Programming ↗
C-Programming covers every topic to learn about C-Sharp thoroughly.
Learn C++ Programming↗
C++ covers every topic to learn about C-Sharp thoroughly.