Breaking News: Grepper is joining You.com. Read the official announcement!

heap , min heap in py

Add Answer

Adventurous Alligator answered on March 11, 2022 Popularity 10/10 Helpfulness 3/10

answer heap , min heap in py

related how to implement heap in python

related python implementation of Min Heap

related python heap min or max

related python heapify

heap , min heap in py

Comment

# A Python program to demonstrate common binary heap operations
  
# Import the heap functions from python library
from heapq import heappush, heappop, heapify 
  
# heappop - pop and return the smallest element from heap
# heappush - push the value item onto the heap, maintaining
#             heap invarient
# heapify - transform list into heap, in place, in linear time
  
# A class for Min Heap
class MinHeap:
      
    # Constructor to initialize a heap
    def __init__(self):
        self.heap = [] 
  
    def parent(self, i):
        return (i-1)/2
      
    # Inserts a new key 'k'
    def insertKey(self, k):
        heappush(self.heap, k)           
  
    # Decrease value of key at index 'i' to new_val
    # It is assumed that new_val is smaller than heap[i]
    def decreaseKey(self, i, new_val):
        self.heap[i]  = new_val 
        while(i != 0 and self.heap[self.parent(i)] > self.heap[i]):
            # Swap heap[i] with heap[parent(i)]
            self.heap[i] , self.heap[self.parent(i)] = (
            self.heap[self.parent(i)], self.heap[i])
              
    # Method to remove minium element from min heap
    def extractMin(self):
        return heappop(self.heap)
  
    # This functon deletes key at index i. It first reduces
    # value to minus infinite and then calls extractMin()
    def deleteKey(self, i):
        self.decreaseKey(i, float("-inf"))
        self.extractMin()
  
    # Get the minimum element from the heap
    def getMin(self):
        return self.heap[0]
  
# Driver pgoratm to test above function
heapObj = MinHeap()
heapObj.insertKey(3)
heapObj.insertKey(2)
heapObj.deleteKey(1)
heapObj.insertKey(15)
heapObj.insertKey(5)
heapObj.insertKey(4)
heapObj.insertKey(45)
  
print heapObj.extractMin(),
print heapObj.getMin(),
heapObj.decreaseKey(2, 1)
print heapObj.getMin()
  
# This code is contributed by Nikhil Kumar Singh(nickzuck_007)

Popularity 10/10 Helpfulness 3/10 Language python

Source: www.geeksforgeeks.org

Tags: heap min-heap python

Link to this answer
Share Copy Link

Contributed on Jul 30 2022

Adventurous Alligator

0 Answers Avg Quality 2/10

Closely Related Answers

how to implement heap in python

Comment

# Python3 program to demonstrate working of heapq
  
from heapq import heapify, heappush, heappop
  
# Creating empty heap
heap = []
heapify(heap)
  
# Adding items to the heap using heappush function
heappush(heap, 10)
heappush(heap, 30)
heappush(heap, 20)
heappush(heap, 400)
  
# printing the value of minimum element
print("Head value of heap : "+str(heap[0]))
  
# printing the elements of the heap
print("The heap elements : ")
for i in heap:
    print(i, end = ' ')
print("\n")
  
element = heappop(heap)
  
# printing the elements of the heap
print("The heap elements : ")
for i in heap:
    print(i, end = ' ')

Popularity 10/10 Helpfulness 2/10 Language python

Source: www.geeksforgeeks.org

Tags: heap

Link to this answer
Share Copy Link

Contributed on Aug 13 2022

Good Grasshopper

0 Answers Avg Quality 2/10

python implementation of Min Heap

Comment

# Python3 implementation of Min Heap
 
import sys
 
class MinHeap:
 
    def __init__(self, maxsize):
        self.maxsize = maxsize
        self.size = 0
        self.Heap = [0]*(self.maxsize + 1)
        self.Heap[0] = -1 * sys.maxsize
        self.FRONT = 1
 
    # Function to return the position of
    # parent for the node currently
    # at pos
    def parent(self, pos):
        return pos//2
 
    # Function to return the position of
    # the left child for the node currently
    # at pos
    def leftChild(self, pos):
        return 2 * pos
 
    # Function to return the position of
    # the right child for the node currently
    # at pos
    def rightChild(self, pos):
        return (2 * pos) + 1
 
    # Function that returns true if the passed
    # node is a leaf node
    def isLeaf(self, pos):
        return pos*2 > self.size
 
    # Function to swap two nodes of the heap
    def swap(self, fpos, spos):
        self.Heap[fpos], self.Heap[spos] = self.Heap[spos], self.Heap[fpos]
 
    # Function to heapify the node at pos
    def minHeapify(self, pos):
 
        # If the node is a non-leaf node and greater
        # than any of its child
        if not self.isLeaf(pos):
            if (self.Heap[pos] > self.Heap[self.leftChild(pos)] or
               self.Heap[pos] > self.Heap[self.rightChild(pos)]):
 
                # Swap with the left child and heapify
                # the left child
                if self.Heap[self.leftChild(pos)] < self.Heap[self.rightChild(pos)]:
                    self.swap(pos, self.leftChild(pos))
                    self.minHeapify(self.leftChild(pos))
 
                # Swap with the right child and heapify
                # the right child
                else:
                    self.swap(pos, self.rightChild(pos))
                    self.minHeapify(self.rightChild(pos))
 
    # Function to insert a node into the heap
    def insert(self, element):
        if self.size >= self.maxsize :
            return
        self.size+= 1
        self.Heap[self.size] = element
 
        current = self.size
 
        while self.Heap[current] < self.Heap[self.parent(current)]:
            self.swap(current, self.parent(current))
            current = self.parent(current)
 
    # Function to print the contents of the heap
    def Print(self):
        for i in range(1, (self.size//2)+1):
            print(" PARENT : "+ str(self.Heap[i])+" LEFT CHILD : "+
                                str(self.Heap[2 * i])+" RIGHT CHILD : "+
                                str(self.Heap[2 * i + 1]))
 
    # Function to build the min heap using
    # the minHeapify function
    def minHeap(self):
 
        for pos in range(self.size//2, 0, -1):
            self.minHeapify(pos)
 
    # Function to remove and return the minimum
    # element from the heap
    def remove(self):
 
        popped = self.Heap[self.FRONT]
        self.Heap[self.FRONT] = self.Heap[self.size]
        self.size-= 1
        self.minHeapify(self.FRONT)
        return popped
 
# Driver Code
if __name__ == "__main__":
     
    print('The minHeap is ')
    minHeap = MinHeap(15)
    minHeap.insert(5)
    minHeap.insert(3)
    minHeap.insert(17)
    minHeap.insert(10)
    minHeap.insert(84)
    minHeap.insert(19)
    minHeap.insert(6)
    minHeap.insert(22)
    minHeap.insert(9)
    minHeap.minHeap()
 
    minHeap.Print()
    print("The Min val is " + str(minHeap.remove()))

Popularity 10/10 Helpfulness 2/10 Language python

Source: www.geeksforgeeks.org

Tags: implementation impl

Link to this answer
Share Copy Link

Contributed on Mar 11 2022

Good Gentoo

0 Answers Avg Quality 2/10

python heap min or max

Comment

Python's heap is a min heap.

Popularity 10/10 Helpfulness 1/10 Language whatever

Source: docs.python.org

Tags: heap

Link to this answer
Share Copy Link

Contributed on Jun 14 2022

Johan

0 Answers Avg Quality 2/10

python heapify

Comment

Input: nums = [1,3,2,3,1]
Output: 2
Explanation: The reverse pairs are:
(1, 4) --> nums[1] = 3, nums[4] = 1, 3 > 2 * 1
(3, 4) --> nums[3] = 3, nums[4] = 1, 3 > 2 * 1

Popularity 10/10 Helpfulness 1/10 Language python

Source: leetcode.com

Tags: python py

Link to this answer
Share Copy Link

Contributed on Mar 28 2023

Mehari Tesfaye

0 Answers Avg Quality 2/10

heap , min heap in py

Contents

More Related Answers

heap , min heap in py

Closely Related Answers

how to implement heap in python

python implementation of Min Heap

python heap min or max

python heapify

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.