#Using Slicing

##def binary_search(array, searchterm):
##
##    while len(array)!= 1:
##
##        midpoint = len(array) // 2
##
##        if searchterm < array[midpoint]:
##
##            array = array[:midpoint]
##        else:
##
##            array = array [midpoint:]
##    return array
            
#Using Markers (Without Slicing)

##def binary_search(array, searchterm):
##
##    left = 0
##
##    right = len(array) - 1
##
##    while left <= right:
##
##        midpoint = (left + right) // 2
##
##        if array[midpoint] < searchterm:
##
##            left = midpoint + 1
##        else:
##
##            right = midpoint - 1
##
##    return(array[midpoint])

#Recursive:
def binary_search(array, searchterm):

    if len(array) == 1:
        return array[0] == searchterm

    mid = len(array) // 2

    if searchterm < array[mid]:
        array = array [:mid]
    else:
        array = array[mid:]

    return binary_search(array, searchterm)
    


file = open("townlist.txt","r")
townlist = []
for line in file:
    town = line.strip()
    town = town.lower()
    townlist.append(town)

sortarray = sorted(townlist)
print(binary_search(sortarray, 'nuneaton'))