문제 링크

정답 :

def solution(l, r):
    answer = []
    
    for i in range(l, r+1):
        check = True
        for s in str(i):
            if s != '5' and s != '0':
                check = False
                break
        if check:
            answer.append(i)
            
    return answer if answer else [-1]

방법 1.

def solution(l, r):
    answer = []
    
    for num in range(l, r + 1):
        if not set(str(num)) - set(['0', '5']):
            answer.append(num)
            
    return answer if answer else [-1]

개선 1.

def solution(l, r):
    answer = []
    
    l -= l % 5
    
    for i in range(l, r+1, 5):
        if not set(str(i)) - set(['0', '5']):
            answer.append(i)
            
    return answer if answer else [-1]

5의 배수만 탐색하면 효율적