Happy numbers | Rosetta Code | #17

URL to the problem page: http://rosettacode.org/wiki/Happy_numbers


A happy number is defined by the following process:

Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1.

Those numbers for which this process ends in 1 are happy numbers, while those that do not end in 1 are unhappy numbers.

Find and print the first 8 happy numbers.

#include <iostream>

using namespace std;

int power(int a, int b) {

    int result = 1;

    for (int i = 0; i < b; i++) {

        result *= a;

    }

    return result;

}

int main()

{

    int number, number2, cnt = 0, digitnumber;

    cout << "First 8 happy numbers are:" << endl;

    for (int i = 1; cnt < 8; i++) {

        number = i;

        while (number != 89) {

            digitnumber = 1;

            number2 = number;

            while (number2 >= 10) {

                number2 /= 10;

                digitnumber++;

            }

            number2 = 0;

            for (int j = digitnumber; j > 0; j--) {

                number2 += power(((number % power(10, j)) / (power(10, (j - 1)))), 2);

            }

            number = number2;

            if (number == 1) {

                cout << i << endl;

                cnt++;

                break;

            }

        }

    }

    return 0;

}

CLICK TO SEE THE OUTPUT.