[proj] 완주하지 못한 선수

파이썬
https://1ets-just-do-it.tistory.com/61

def solution(participant, completion):
    participant.sort()
    completion.sort()
    # print(list(zip(participant, completion)))
    
    for a,b in zip(participant, completion):
        if a!=b:
            return a
    
    return participant[-1]

def solution(participant, completion):
    dic = {}
    answer = []
    for i in participant: # 참가자 횟수 +1
        if i not in dic.keys():
            dic[i]=1
        else:
            dic[i]+=1
    for i in completion: # 완주하면 -1
            dic[i]-=1
        
    for i in dic.keys():
        if dic[i]>0: # 순회하면서 0보다 크면 완주 못한거임
            answer.append(i)
    return "".join(answer)

자바스크립트
https://school.programmers.co.kr/questions/64622