Question

我目前正在上edx课程，任务之一是实现简单的min-heap。

必须使用一个元组列表来实现堆，该元组是不可变的，因此无法在原位置进行更改。

元组的第一个元素是键
第二个元素是要检查的最小值的变量
元素3是无关的

我的解决方案在下面，但是由于我是python的新手，我想知道一个经验丰富的程序员将如何实现它，但是在元组列表的现有约束下-无法使用其他数据结构。

def heap_add_or_replace(heap, triplet):
match=0
for tup in heap[:]:
    if tup[0]==triplet[0]:
        match+=1
        if tup[1] > triplet[1]:
            heap.remove(tup)
            heap.append(triplet)
            break
if  match==0:
    heap.append(triplet)

heap.sort(key=lambda x:x[1])

该课程的测试如下：

#
# AUTOGRADER TEST - DO NOT REMOVE
#

triplet_heap=list()

heap_add_or_replace(triplet_heap,((2,3),0.9,(1,0)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((7,2),0.3,(2,2)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((3,2),1,(2,2)))
print("the new heap is: "+str(triplet_heap))

print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((7,2),0.2,(2,3)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((1,2),0.3,(2,3)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((1,2),0.1,(2,3)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((1,2),0.05,(2,0)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((4,6),2,(2,3)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((1,2),0.01,(2,0)))
print("the new heap is: "+str(triplet_heap))

heap_add_or_replace(triplet_heap,((4,6),9,(2,3)))
print("the new heap is: "+str(triplet_heap))

和预期结果：

the new heap is: [((2, 3), 0.9, (1, 0))]
the new heap is: [((7, 2), 0.3, (2, 2)), ((2, 3), 0.9, (1, 0))]
the new heap is: [((7, 2), 0.3, (2, 2)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((7, 2), 0.3, (2, 2)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((7, 2), 0.2, (2, 3)), ((1, 2), 0.3, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((1, 2), 0.1, (2, 3)), ((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((1, 2), 0.05, (2, 0)), ((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2))]
the new heap is: [((1, 2), 0.05, (2, 0)), ((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2)), ((4, 6), 2, (2, 3))]
the new heap is: [((1, 2), 0.01, (2, 0)), ((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2)), ((4, 6), 2, (2, 3))]
the new heap is: [((1, 2), 0.01, (2, 0)), ((7, 2), 0.2, (2, 3)), ((2, 3), 0.9, (1, 0)), ((3, 2), 1, (2, 2)), ((4, 6), 2, (2, 3))]

python中的简单最小堆使用带元组（不可变）元素的列表

0 个答案: