最小的k个数-Python版

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