프로그래머스 lv1 실패율

1. 개요

• https://school.programmers.co.kr/learn/courses/30/lessons/42889

2. 풀이

def solution(N, stages):
    notCleared, reached = [0]*(N+2), [0]*(N+3)
    failRate = [0]*(N+2)
    
    for stage in stages:
        notCleared[stage] += 1
        reached[stage+1] -= 1
        reached[0] += 1
    
    # 누적합을 통해 도달한 숫자를 빠르게 구해보자
    for i in range(1, N+2):
        reached[i] += reached[i-1]
    
    for i in range(N+2):
        if reached[i]==0:
            failRate[i] = 0
        else:
            failRate[i] = notCleared[i]/reached[i]
    
    return sorted(range(1,N+1), key=lambda x: failRate[x], reverse=True)