실패율
정렬시킨 뒤 이진 탐색으로 개수 세기
from bisect import bisect_left, bisect_right
# 1, 2, 2, 2, 3, 3, 4, 6
d = dict()
def solution(N, stages):
stages.sort()
for i in range(1, N+1):
fail = bisect_right(stages, i) - bisect_right(stages, i-1)
denominator = len(stages) - bisect_right(stages, i-1)
d[i] = fail / denominator if denominator != 0 else 0
dd = sorted(d.items(), key = lambda x: (-x[1]))
return [i[0] for i in dd]
