题目：

题解：

import numpy as np from bisect import bisect_left  class Solution:     max_len =  10000     c = []     buckets = []      def countSmaller(self, nums: List[int]) -> List[int]:         self.c = [0 for _ in range(len(nums) + 5)]         counts = [0 for _ in range(len(nums))]         nums = self.discretization(nums)         for i in range(len(nums) - 1, -1, -1):             num = nums[i]             counts[i] = self.query(num-1)             self.updateC(num)         return counts      def updateC(self, pos):         while pos < len(self.c):             self.c[pos] += 1             pos += self.lowbit(pos)      def lowbit(self, x):         """获取更新范围"""         return x & (-x)      def query(self, pos):         """查询前缀和"""         val = 0         while pos > 0:             val += self.c[pos]             pos -= self.lowbit(pos)         return val      def getMappingList(self, nums):         """列表去重排序"""         return list(sorted(set(nums)))      def discretization(self, nums):         """将nums进行离散化变换"""         mapping = self.getMappingList(nums)         return [bisect_left(mapping, num) + 1 for num in nums]