Program to check for Happy Number

Program to check for Happy Number

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If a number is happy, then all members of its sequence are happy; if a number is unhappy, all members of the sequence are unhappy.

For example, 19 is happy, as the associated sequence is:

1² + 9² = 82

8² + 2² = 68

6² + 8² = 100

1² + 0² + 0² = 1.

The 143 happy numbers up to 1,000 are:

1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49, 68, 70, 79, 82, 86, 91, 94, 97, 100, 103, 109, 129, 130, 133, 139, 167, 176, 188, 190, 192, 193, 203, 208, 219, 226, 230, 236, 239, 262, 263, 280, 291, 293, 301, 302, 310, 313, 319, 320, 326, 329, 331, 338, 356, 362, 365, 367, 368, 376, 379, 383, 386, 391, 392, 397, 404, 409, 440, 446, 464, 469, 478, 487, 490, 496, 536, 556, 563, 565, 566, 608, 617, 622, 623, 632, 635, 637, 638, 644, 649, 653, 655, 656, 665, 671, 673, 680, 683, 694, 700, 709, 716, 736, 739, 748, 761, 763, 784, 790, 793, 802, 806, 818, 820, 833, 836, 847, 860, 863, 874, 881, 888, 899, 901, 904, 907, 910, 912, 913, 921, 923, 931, 932, 937, 940, 946, 964, 970, 973, 989, 998, 1000.

The happiness of a number is unaffected by rearranging the digits, and by inserting or removing any number of zeros anywhere in the number.

The program to check if a number is Happy or not is given below : -

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import java.util.Scanner;

class Happy

{

    Scanner S = new Scanner(System.in);

    int no;

    public boolean isHappy(int x)

    {

        int y = x;

        int sum = sumofdigitsquare(y);

        int u=0;

        while(sum>9)

        sum = sumofdigitsquare(sum);

        if(sum==1)

        return true;

        else

        return false;

    }

    public int sumofdigitsquare(int x)

    {

        int sum = 0;

        while(x>0)

        {

            sum = sum +((x%10)*(x%10));

            x=x/10;

        }

        return sum;

    }

    public void main()

    {

        System.out.println("Enter the number to be checked for Happy :-");

        if(isHappy(S.nextInt()))

        System.out.println("It is a Happy Number");

        else 

        System.out.println("Tis not a Happy Number");

    }

}

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For other Number checking programs, check my other blog...<Click Here>