import random
def generate_big_root_heap(li,low,hight):
i = low
j = 2 * i + 1
tmp = li[i]
while j <= hight:
if j + 1 <= hight and li[j+1] > li[j]:
j = j + 1
if li[j] > tmp:
li[i] = li[j]
i = j
j = 2 * i + 1
else:
break
li[i] = tmp
def generate_low_root_heap(li,low,hight):
i = low
j = 2 * i + 1
tmp = li[low]
while j <= hight:
if j + 1 <= hight and li[j+1] < li[j]:
j = j + 1
if li[j] < tmp:
li[i] = li[j]
i = j
j = 2 * i + 1
else:
break
li[i] = tmp
def topk(li,k):
heap = li[:k]
for i in range((k-1-1)//2,-1,-1):
generate_low_root_heap(heap,i,k-1)
for i in range(k,len(li)-1):
if li[i] > heap[0]:
heap[0] = li[i]
generate_low_root_heap(heap,0,k-1)
for i in range(k-1,-1,-1):
heap[i], heap[0] = heap[0], heap[i]
generate_low_root_heap(heap,0,i-1)
return heap
def main():
li = [i for i in range(100)]
random.shuffle(li)
print(li)
heap = topk(li,10)
print(heap)
if __name__ == '__main__':
main()
