Questions tagged [min-heap]
181 questions
3
votes
1 answer
What is wrong with my Heapsort algorithm for building a min heap?
I'm prepping for software developer interviews and have been working on algorithm problems. My book shows a Heapsort algorithm that can sort an unordered array in increasing order. I'm trying to modify it so it can sort with a min heap. But when I…
MNRC
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3
votes
1 answer
Is Min Heap Function
I want to write a function that tells me whether a given list is a min heap.
What I have written so far:
def is_min_heap(L):
return _is_min_heap(L, 0)
def _is_min_heap(L, i):
if
#base case
else:
return (L[i] <…
Mat.S
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2
votes
1 answer
Constructing Min/Max Binary Heap
Given an inorder-traversal list, what's the best way to create a Binary Min/Max Heap?
I'm trying to confine with the following constructs:
No array to be used in the binary-heap. Implementation is node-based.
BinaryNode { value, parent, l_child,…
gvaish
- 9,374
- 3
- 38
- 43
2
votes
1 answer
Find K Pairs with Smallest Sums
The question is this:
You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.
Define a pair (u, v) which consists of one element from the first array and one element from the second array.
Return the k pairs…
user19089374
2
votes
1 answer
Is this logic possible? (concerns: binary min heap, priority queue, insert at index 0 but root is at index 1)
I have a working code (with the required efficiency) for a binary min heap priority queue that keeps index 0 empty and has the root node at index 1 (children are 2i and 2i+1). I insert the new value into the heap at the first available empty space…
python_girl
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- 4
2
votes
1 answer
Overloading comparison operators in custom class for priority_queue
I am trying to create a min heap of "number" using priority_queue. "number" is a class defined by me that has three private variables:
int value; //This holds the value to be read in the heap
vector list; //This holds the vector…
Powerracer251
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2
votes
1 answer
Why do some people override the comparator function for implementing minheap using PriorityQueue even though PQ in java is a min-heap by default?
I searched a bit and looks like a PriorityQueue work like a min-heap by default in Java. So, why override the comparator? I have seen people do it even for integers. Am I missing something here? I am new to java.
I tried both of the below codes to…
Saikip
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- 4
2
votes
1 answer
Min/Max Heap implementation in Python
This is my implementation of a MinHeap and MaxHeap in python. This uses a comparator to reverse the sequence of storage in the MaxHeap
import heapq
class MinHeap:
def __init__(self):
self.heap = []
def push(self, item):
…
Melissa Stewart
- 3,483
- 11
- 49
- 88
2
votes
1 answer
MinHeap/MaxHeap implementation in Python
I scoured the web to come up with this implementation of MinHeap and Maxheap in Python.
import heapq
class MinHeap:
def __init__(self):
self.heap = []
def push(self, item):
heapq.heappush(self.heap, item)
def…
Melissa Stewart
- 3,483
- 11
- 49
- 88
2
votes
1 answer
Running top k elements in a sorted, fixed size list / python
I am trying to keep a list of top k elements of a large set of tuples. Since keeping it in the memory is impossible, I want to use a fixed size list to keep only the top k values (with the keys). I have tried to use min heap but python's heap is…
dusa
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2
votes
0 answers
In-place algorithm for creating min-heap of a Binary search tree
I am trying to implement in-place algorithm of min-heap. I converted the BST to sorted linked list, and following is the code snippet
public void inorder(Node root) {
if (isEmpty(root))
return;
inorder(root.left);
…
Shashank Agrawal
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2
votes
1 answer
Max and Min heap with the same elements
Consider the following example. I am adding random numbers to min heap and at the same time I am adding the same numbers in the same order to the max heap. So at the end those 2 heaps will have the same numbers with difference one being min heap and…
kvway
- 494
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2
votes
1 answer
Min-HeapSort does not sort after ~350 elements
I'm implementing a heapSort, using min-heap, and it sorts fine, below ~350 elements. Once the array has approximately 350 elements, it doesn't sort correctly. I'm not sure where the error lies, but I believe it might have to do with extractMin(), or…
Roman Lopez
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2
votes
1 answer
What is the time complexity of finding the minimum element in a min heap?
I was reading Problem1 (Part-b) mentioned in this document:
Finding the minimum element of a binary min heap takes logarithmic time:
T/F?
It should be true, because when we construct a max-heap, the time complexity is O(logn)as mentioned here.…
John Lui
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2
votes
2 answers
Use PriorityQueue as a minHeap
When trying to solve this problem https://www.hackerrank.com/challenges/cut-the-tree
I was trying to always pick and cut a leaf and then combine its weight to the node that it connects.
I was using a PriorityQueue to store all the nodes, and using…
1736964698
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