[Python][프로그래머스][Level3] 보석 쇼핑

def solution(gems):
    answer=[]
    check=set()
    ck = {gem:0 for gem in set(gems)}
    
    start=0
    for end, gem in enumerate(gems):
        ck[gem]+=1
        check.add(gem)
        if len(check)==len(ck):
            answer.append([start+1,end+1])
            while start<end and ck[gems[start]]>1:
                ck[gems[start]]-=1
                start+=1
                answer.append([start+1,end+1])            
            
    return sorted(answer,key=lambda x: x[1]-x[0])[0]