python查找第k小元素代码分享

复制代码 代码如下:# -*- coding: utf-8 -*- from random import randintfrom math import ceil, floor def _partition(A, l, r, i): “””以A[i]为主元划分数组A[l..r],使得: A[l..m-1] <= A[m] < A[m+1..r] “”” A[i], A[r] = A[r], A[i] # i交换到末位r,作为主元 pivot = A[r] # 主元 m = l # 索引标记 for n in xrange(l, r): #