SRM484 - div2 - level two

srm484_div2_level2.py

#! /usr/bin/env python
# -*- coding: utf-8 -*-

"""SRM484 - div2 - level two

When cat Taro and rabbit Hanako were practicing hard for SRM 484, 
they noticed an interesting property of 484. 
They called it Rabbit Number.

Let S(n) be the sum of the digits of n. For example, 
S(484) = 4+8+4 = 16 and S(22) = 2+2 = 4. A positive integer x is 
called a Rabbit Number if S(x*x) = S(x)*S(x). For example, 
22 is a Rabbit Number because S(484) = S(22)*S(22).

Return the number of Rabbit Numbers between low and high, inclusive.

Definition:
    Class: RabbitNumber
    Method: theCount
    Parameters: int, int
    Returns: int
    Method signature: int theCount(int low, int high)
"""

class RabbitNumber(object):
    """Afraid Of Even

    Constraints:
        - low will be between 1 and 1,000,000,000, inclusive.
        - high will be between low and 1,000,000,000, inclusive.

    >>> rabbit = RabbitNumber()
    >>> print rabbit.theCount(22, 22)
    1
    >>> print rabbit.theCount(484, 484)
    0
    >>> print rabbit.theCount(1, 58)
    12
    >>> print rabbit.theCount(58, 484)
    24
    >>> print rabbit.theCount(1000000000, 1000000000)
    1
    """

    def __init__(self):
        pass

    def theCount(self, low, high):
        def s(n):
            return sum([int(i) for i in str(n)])

        r = 0
        for i in range(low, high+1):
            if s(i*i) == s(i)*s(i):
                r += 1
        return r

if __name__ == '__main__':
    import doctest
    doctest.testmod()