우박수열 정적분

https://school.programmers.co.kr/learn/courses/30/lessons/134239

프로그래머스

 

def solution(k, ranges):
    points = [k]
    while k != 1:
        if k % 2 == 0:
            k //= 2
        else:
            k = 3 * k + 1
        points.append(k)
    return [-1 if a > (c := len(points) + b - 1) else sum((points[i] + points[i + 1]) / 2 for i in range(a, c)) for a, b in ranges]

 

보기 좋게 두 개의 함수로.. 

def collatz(k):
    points = [k]
    while k != 1:
        if k % 2 == 0:
            k //= 2
        else:
            k = 3 * k + 1
        points.append(k)
    return points


def solution(k, ranges):
    points = collatz(k)
    answer = []
    for a, b in ranges:
        c = len(points) + b - 1
        if a > c:
            answer.append(-1)
        else:
            temp = 0
            for i in range(a, c):
                temp += (points[i] + points[i + 1]) / 2
            answer.append(temp)
    return answer