Skip to content

Courses
Tutorials
Practice
Contests

Python Tutorial
Interview Questions
Python Quiz
Python Glossary
Python Projects
Practice Python
Data Science With Python
Python Web Dev
DSA with Python
Python OOPs

Merge two sorted arrays in constant space using Min Heap

Merge two sorted arrays in Python using heapq

Last Updated : 04 Mar, 2023

Comments

Improve

Suggest changes

Like Article

Like

Report

Given two sorted arrays, the task is to merge them in a sorted manner. Examples:

Input :  arr1 = [1, 3, 4, 5]            arr2 = [2, 4, 6, 8] Output : arr3 = [1, 2, 3, 4, 4, 5, 6, 8]  Input  : arr1 = [5, 8, 9]            arr2 = [4, 7, 8] Output : arr3 = [4, 5, 7, 8, 8, 9]

This problem has existing solution please refer Merge two sorted arrays link. We will solve this problem in python using heapq.merge() in a single line of code.

Implementation:

Python3

   # Function to merge two sorted arrays
from heapq import merge
 
def mergeArray(arr1,arr2):
    return list(merge(arr1, arr2))
 
# Driver function
if __name__ == "__main__":
    arr1 = [1,3,4,5]  
    arr2 = [2,4,6,8]
    print (mergeArray(arr1, arr2))
 
  

Output

[1, 2, 3, 4, 4, 5, 6, 8]

The time complexity is O(n log n).

The space complexity is O(n).

Properties of heapq module ?

This module provides an implementation of the heap queue algorithm, also known as the priority queue algorithm. To create a heap, use a list initialized to [], or you can transform a populated list into a heap via function heapify().The following functions are provided:

heapq.heappush(heap,item) : Push the value item onto the heap, maintaining the heap invariant.
heapq.heappop(heap) : Pop and return the smallest item from the heap, maintaining the heap invariant. If the heap is empty, IndexError is raised. To access the smallest item without popping it, use heap[0].
heapq.heappushpop(heap, item) : Push item on the heap, then pop and return the smallest item from the heap. The combined action runs more efficiently than heappush() followed by a separate call to heappop().
heapq.heapify(x) : Transform list x into a heap, in-place, in linear time.
heapq.merge(*iterables) : Merge multiple sorted inputs into a single sorted output (for example, merge timestamped entries from multiple log files). Returns an iterator over the sorted values.

Merge two sorted arrays in constant space using Min Heap

GeeksforGeeks

Improve

Article Tags :

Arrays
DSA
Heap
Python
array-merge

Practice Tags :

Arrays
Heap
python

Similar Reads

Merge k Sorted Arrays Using Min Heap

Given k sorted arrays of possibly different sizes, merge them and print the sorted output.Examples: Input: k = 3 arr[][] = { {1, 3}, {2, 4, 6}, {0, 9, 10, 11}} ;Output: 0 1 2 3 4 6 9 10 11 Input: k = 2 arr[][] = { {1, 3, 20}, {2, 4, 6}} ;Output: 1 2 3 4 6 20 We have discussed a solution that works f

Merge two sorted arrays in constant space using Min Heap

Given two sorted arrays, we need to merge them with O(1) extra space into a sorted array, when N is the size of the first array, and M is the size of the second array. Example : Input: arr1[] = {10}; arr2[] = {2, 3};Output: arr1[] = {2} arr2[] = {3, 10} Input: arr1[] = {1, 5, 9, 10, 15, 20}; arr2[]

Merge two sorted arrays using Priority queue

Given two sorted arrays A[] and B[] of sizes N and M respectively, the task is to merge them in a sorted manner. Examples: Input: A[] = { 5, 6, 8 }, B[] = { 4, 7, 8 }Output: 4 5 6 7 8 8 Input: A[] = {1, 3, 4, 5}, B] = {2, 4, 6, 8} Output: 1 2 3 4 4 5 6 8 Input: A[] = {5, 8, 9}, B[] = {4, 7, 8} Outpu

Sorted merge in one array

Given two sorted arrays, A and B, where A has a large enough buffer at the end to hold B. Merge B into A in sorted order. Examples: Input : a[] = {10, 12, 13, 14, 18, NA, NA, NA, NA, NA} b[] = {16, 17, 19, 20, 22};; Output : a[] = {10, 12, 13, 14, 16, 17, 18, 19, 20, 22} One way is to merge the two

Merging two unsorted arrays in sorted order

Write a SortedMerge() function that takes two lists, each of which is unsorted, and merges the two together into one new list which is in sorted (increasing) order. SortedMerge() should return the new list. Examples : Input : a[] = {10, 5, 15} b[] = {20, 3, 2} Output : Merge List : {2, 3, 5, 10, 15,

Merge two sorted arrays

Given two sorted arrays, the task is to merge them in a sorted manner.Examples: Input: arr1[] = { 1, 3, 4, 5}, arr2[] = {2, 4, 6, 8} Output: arr3[] = {1, 2, 3, 4, 4, 5, 6, 8} Input: arr1[] = { 5, 8, 9}, arr2[] = {4, 7, 8} Output: arr3[] = {4, 5, 7, 8, 8, 9} Table of Content [Naive Approach] Concaten

K-th Element of Merged Two Sorted Arrays

Given two sorted arrays of sizes m and n respectively, the task is to find the element that would be at the k-th position in the final sorted array formed by merging these two arrays. Examples: Input: a[] = [2, 3, 6, 7, 9], b[] = [1, 4, 8, 10], k = 5Output: 6Explanation: The final sorted array is [1

3-way Merge Sort in Python

Merge sort involves recursively splitting the array into 2 parts, sorting, and finally merging them. A variant of merge sort is called 3-way merge sort where instead of splitting the array into 2 parts we split it into 3 parts. Examples: Input: arr = [12, 11, 13, 5, 6, 7]Output: [5, 6, 7, 11, 12, 13

K-ary Heap using Python

Ak-ary heap is also called n-ary or d-ary heap. It is a generalized form of the binary heap structure where each node has up to K children, unlike the binary heap structure with only 2 children. Because of this feature, the k-ary heap is a flexible and efficient data structure for priority queue imp

Union of Two Sorted Arrays

Given two sorted arrays a[] and b[], the task is to to return union of both the arrays in sorted order. Union of two arrays is an array having all distinct elements that are present in either array. The input arrays may contain duplicates. Examples: Input: a[] = {1, 1, 2, 2, 2, 4}, b[] = {2, 2, 4, 4

Corporate & Communications Address:

A-143, 7th Floor, Sovereign Corporate Tower, Sector- 136, Noida, Uttar Pradesh (201305)

Registered Address:

K 061, Tower K, Gulshan Vivante Apartment, Sector 137, Noida, Gautam Buddh Nagar, Uttar Pradesh, 201305

Advertise with us

Company
About Us
Legal
Privacy Policy
In Media
Contact Us
Advertise with us
GFG Corporate Solution
Placement Training Program

Languages
Python
Java
C++
PHP
GoLang
SQL
R Language
Android Tutorial
Tutorials Archive

DSA
Data Structures
Algorithms
DSA for Beginners
Basic DSA Problems
DSA Roadmap
Top 100 DSA Interview Problems
DSA Roadmap by Sandeep Jain
All Cheat Sheets

Data Science & ML
Data Science With Python
Data Science For Beginner
Machine Learning
ML Maths
Data Visualisation
Pandas
NumPy
NLP
Deep Learning

Web Technologies
HTML
CSS
JavaScript
TypeScript
ReactJS
NextJS
Bootstrap
Web Design

Python Tutorial
Python Programming Examples
Python Projects
Python Tkinter
Python Web Scraping
OpenCV Tutorial
Python Interview Question
Django

Computer Science
Operating Systems
Computer Network
Database Management System
Software Engineering
Digital Logic Design
Engineering Maths
Software Development
Software Testing

DevOps
Git
Linux
AWS
Docker
Kubernetes
Azure
GCP
DevOps Roadmap

System Design
High Level Design
Low Level Design
UML Diagrams
Interview Guide
Design Patterns
OOAD
System Design Bootcamp
Interview Questions

Inteview Preparation
Competitive Programming
Top DS or Algo for CP
Company-Wise Recruitment Process
Company-Wise Preparation
Aptitude Preparation
Puzzles

School Subjects
Mathematics
Physics
Chemistry
Biology
Social Science
English Grammar
Commerce
World GK

GeeksforGeeks Videos
DSA
Python
Java
C++
Web Development
Data Science
CS Subjects

@GeeksforGeeks, Sanchhaya Education Private Limited, All rights reserved

We use cookies to ensure you have the best browsing experience on our website. By using our site, you acknowledge that you have read and understood our Cookie Policy & Privacy Policy

Improvement

Suggest Changes

Help us improve. Share your suggestions to enhance the article. Contribute your expertise and make a difference in the GeeksforGeeks portal.

geeksforgeeks-suggest-icon

Create Improvement

Enhance the article with your expertise. Contribute to the GeeksforGeeks community and help create better learning resources for all.

geeksforgeeks-improvement-icon

Suggest Changes

min 4 words, max Words Limit:1000

Thank You!

Your suggestions are valuable to us.

What kind of Experience do you want to share?

Interview Experiences

Admission Experiences

Career Journeys

Work Experiences

Campus Experiences

Competitive Exam Experiences