题目
输入n个整数，找出其中最小的K个数。例如输入4,5,1,6,2,7,3,8这8个数字，则最小的4个数字是1,2,3,4,。（牛客网上要求结果有序）
解法1，使用快排思想
1 # -*- coding:utf-8 -*-
2 class Solution:
3 def GetLeastNumbers_Solution(self, tinput, k):
4 # write code here
5 smallk=[]
6 length = len(tinput)
7 if k<=0 or k>length or length==0:
8 return smallk
9 if k==length:
10 return sorted(tinput)
11 left =0
12 right=length-1
13 while left <= right: # 要<=
14 small = self.quicksort(tinput,left,right)
15 if small == k:
16 for i in range(k):
17 smallk.append(tinput[i])
18 break
19 if small >k:
20 right = small-1
21 if small <k:
22 left = small+1
23 return sorted(smallk)
24 def quicksort(self,tinput,left,right):
25 small =left -1
26 temp = tinput[right]
27 for index in range(left,right,1):
28 if tinput[index]<temp:
29 small+=1
30 if small != index:
31 tinput[small],tinput[index] = tinput[index] ,tinput[small]
32 small +=1
33 # tinput[small],temp = temp,tinput[small]不能交换tinput[right]
34 tinput[small], tinput[right] = tinput[right], tinput[small]
35 return small
解法2，创建一个k大小的容器（略），适合海量数据