[프로그래머스/Python] 콜라츠 추측

문제

https://school.programmers.co.kr/learn/courses/30/lessons/12943

프로그래머스

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1. 재귀

global cnt
cnt = 0
def solution(num):
    global cnt
    if cnt > 500:
        return -1
    if num == 1:
        return cnt
    if num%2 == 0:
        cnt += 1
        return solution(num//2)
    else:
        cnt += 1
        return solution(num*3 + 1)

 

2. 반복문

def solution(num):
    cnt = 0
    while num != 1:
        if num%2 == 0:
            cnt += 1
            num = num//2
        else:
            cnt += 1
            num = num*3 + 1
    return cnt if cnt <= 500 else -1