The smallest number of k (the largest heap, massive data)

Title description

Enter n integers and find the smallest K number. For example, if you enter the 8 numbers 4,5,1,6,2,7,3,8, the smallest 4 numbers are 1,2,3,4,.

Idea: To maintain a maximum heap with a size of k, first initialize the first k numbers, and then slide the window. If it is larger than the top of the heap, discard it directly, exchange if it is smaller than the top of the heap, and then adjust the heap.

 

# -*- coding:utf-8 -*-
class Solution:
    def GetLeastNumbers_Solution(self, tinput, k):
        # write code here
        heap = self.Build_Heap(tinput[:k])
        for i in range(k, len(tinput)):
            if tinput[i] >= heap[0]:
                continue
            else:
                heap[0] = tinput[i]
                for i in range(k-1,-1,-1):
                    self.Adjust_Heap(heap, 0, k)
        print heap
        return heap
        
    def Adjust_Heap(self, tinput, root, heap_size):
        left = 2*root+1
        right = left + 1
        larger = root
        if left < heap_size and tinput[left] > tinput[root]:
            larger = left
        if right < heap_size and tinput[right] > tinput[root]:
            larger = right
        if larger != root:
            tinput[root], tinput[larger] = tinput[larger], tinput[root]
            self.Adjust_Heap(tinput, larger, heap_size)
 
    def Build_Heap(self, heap):
        HeapSize = len(heap)
        for i in range((HeapSize-1)//2, -1, -1):
            self.Adjust_Heap(heap,i, HeapSize)
        return heap
 
s = [4,5,1,6,2,7,3,8,435,32,13,5,2,99,0,-67,-7,56,35,637,73,2]
m = Solution()
m.GetLeastNumbers_Solution(s, 8)