1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13

def solution(phone_book):
    answer = True
    arr =dict() 
    for phone_number in phone_book:
        arr[phone_number] = True

    for phone_number in phone_book:
        temp=""
        for num in phone_number:
            temp +=num  
            if temp in arr and temp!=phone_number:
                answer = False
    return answer