guessnumber.py

# A solution to the problem stated in 
# https://www.codeeval.com/browse/170/

import math


def middleNumber(a, b):
    """ Finds the middle integer between a and b.
    If it is not a round number it rounds up to the 
    next integer.
    
    """
    middle = a + (b-a) / 2.0
    return math.ceil(middle)

def play(num, steps):
    """ Performs a guess number play.
    'num' is the range number and 'steps'
    is a string with a sequence of steps.
    
    """
    interval = [0, num]
    for step in steps.split():
        middle = middleNumber(interval[0], interval[1])
        
        if step == 'Lower':
            interval[1] = middle - 1
        elif step == 'Higher':
            interval[0] = middle + 1
        else:
            print(middle)


# Perform the following plays
play(100, 'Lower Lower Higher Lower Lower Lower Yay!')
play(948, 'Higher Lower Yay!')