[PRO] 자동완성

from collections import defaultdict

def solution(words):
    answer = 0
    
    cnt_defaultdict = defaultdict(int)
    
    # 1,000,000
    for word in words:
        for i in range(1,len(word)+1):
            cnt_defaultdict[word[:i]] += 1
    
    for word in words:
        for i in range(1,len(word)+1):
            if cnt_defaultdict[word[:i]] == 1:
                break
        answer += i
    
    return answer