binary heap/Give the class a max value

Question

Below is what I have done but it Does not handle the max requirement on insert.

how do I Give the class a max value and check it in the insert and then remove the least significant element. Then figure out what is the least significant element in the implementation.

Having some issues trying to figure this out.

import math
import random

class BinaryHeap:
def __init__(self, array, direction=1, size=100):
    if(size > len(array)):
        self.size = len(array)
    else:
        self.size = size;
    self.bBinaryHeap = array[:]
    if 0 < direction:
        self.compare = self.greater
    else:
        self.compare = self.less
    self.buildBinaryHeap()

def node(self, index):
    return (index << 1) + 1

def parent(self, index):
    return (index - 1) >> 1

def bBinaryHeapifyDown(self, index): 
    swap = self.bBinaryHeap[index]
    while self.node(index) < self.size:
        node = self.node(index)
        if node + 1 < self.size and self.compare(self.bBinaryHeap[node], self.bBinaryHeap[node + 1]) > 0:
            node += 1
        if self.compare(swap, self.bBinaryHeap[node]) > 0:
            self.bBinaryHeap[index] = self.bBinaryHeap[node];
        else:
            break
        index = node
    self.bBinaryHeap[index] = swap

def upheapify(self, index):  
    while 0 < index and self.compare(self.bBinaryHeap[index], self.bBinaryHeap[self.parent(index)]) < 0:
        parent = self.parent(index)
        swap = self.bBinaryHeap[parent]
        self.bBinaryHeap[parent] = self.bBinaryHeap[index]
        self.bBinaryHeap[index] = swap
        index = parent

def buildBinaryHeap(self):
    indices = range(0, int(self.size / 2))
    reversed(indices)
    for index in indices:
        self.bBinaryHeapifyDown(index)

def insert(self, value):
    self.shrink()
    index = self.size
    self.bBinaryHeap[index] = value
    self.size += 1
    self.upheapify(index)

def search(self, value):
    for index in range(self.size):
        if self.bBinaryHeap[index] == value:
            return index

def delete(self, value):
    index = self.search(value)
    self.size -= 1
    self.bBinaryHeap[index] = self.bBinaryHeap[self.size]
    parent = self.parent(index)
    if (index == 0) or (self.compare(self.bBinaryHeap[parent], self.bBinaryHeap[index]) < 0):
        self.bBinaryHeapifyDown(index)
    else:
        self.upheapify(index)

def shrink(self):
    capacity = len(self.bBinaryHeap)
    if capacity == self.size:
        self.bBinaryHeap.extend([0] * capacity)

def greater(self, value1, value2):
    if value1 == value2:
        return 0
    elif value1 < value2:
        return 1
    elif value1 > value2:
        return -1

def less(self, value1, value2):
    if value1 == value2:
        return 0
    elif value1 < value2:
        return -1
    elif value1 > value2:
        return 1

def getLevel(self, index):
    return int(math.floor(math.log(index + 1, 2)))

def displayBinaryHeap(self):
    printBinaryHeap = str(self.bBinaryHeap)
    height = self.getLevel(self.size)
    previous = -1
    for index in range(self.size):
        getLevel = self.getLevel(index)
        n = height - getLevel
        indent = int(math.pow(2, n + 1) - 2)
        spacing = 2 * indent
        if getLevel != previous:
            printBinaryHeap += '\n'
            printBinaryHeap += ' ' * indent
            previous = getLevel
        else:
            printBinaryHeap += ' ' * spacing
        printBinaryHeap += '%4d' % self.bBinaryHeap[index]
    print(printBinaryHeap)



if __name__ == "__main__":
size =10
array = [random.randint(0, 100) for i in range(size)]
bBinaryHeap = BinaryHeap(array, 1, 100)
print('Binary bBinaryHeap:')
bBinaryHeap.displayBinaryHeap()

7stud · Answer 1 · 2015-12-07T00:27:36.167

Your code has numerous indentation errors. In python, indentation counts.

As for this code:

if 0 < direction:
    self.compare = self.greater
else:
    self.compare = self.less

self.greater and self.less don't exist. You are doing the equivalent of this:

x = elephant

That's nice, but unless you've set the variable elephant to some value prior to that line, that is an error.

how do I Give the class a max value

class BinaryHeap:
    pass

BinaryHeap.max = 10
print(BinaryHeap.max)

--output:--
10

and check it in the insert

class BinaryHeap:
    max = 10

    def insert(self):
        print(self.max)


bh = BinaryHeap()
bh.insert()

--output:--
10

then remove the least significant element

x = 0b1111
print(x) #15

y = x >> 1
print("{:b}".format(y))  #111
print(y)  #7

Then figure out what is the least significant element in the implementation

x = 0b1110
print(x)  #=>14

b_str = "{:b}".format(x)
print(repr(b_str)) #=> '1110'

for direction in [1, -1]:
    if direction > 0:
        least_signif = b_str[-1]
    else:
        least_signif = b_str[0]

    print(least_signif)


--output:--
0
1

how would I take that and put it into my code, I see what your doing. — mike 4332, Dec 07 '15 at 00:16

binary heap/Give the class a max value

1 Answers1