Merge sort is an O(n log n) comparison-based sorting algorithm.

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Merge sort Python implementation

Is this efficient? ...
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Bottom up (iterative) mergesort in C

I have this C implementation of the bottom-up (iterative) mergesort: mergesort.h: ...
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Merging two files containing sorted numbers into one

The task is to merge 2 text files containing sorted integers into one file. Each number in both files is stored in new line(there are no empty lines,and only numbers are stored). Requirements are that ...
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Merge two already sorted linked list

This is code to merge two sorted linked lists. l1 and l2 are sorted. While calling the merge function via ...
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Mergesort algorithm in C

I have this mergesort implementation that has exactly the same API as qsort: mergesort.h: ...
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Memory/performance of merge sort code

I wrote up merge sort code for some late night snack. I have gotten it working, but was just looking learn if I was missing anything in terms of efficiency. Could this code be significantly improved ...
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Merging 3 sorted linked lists

I already know how to merge two linked list, but I needed to code a function that'll merge three already sorted linked lists into one. I wrote a code and it is working fine, it takes care of null ...
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2answers
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Recurrent merge sort (without recursion)

For educational purpose I implement recurrent merge sort without recursion. The algorithm idea seems absolutely clear but my implementation appears to be really slow: 5 seconds to sort 10,000 values;...
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Mergesorting a stack in Java - a new algorithm

(See the previous iteration.) Now I have implemented a stack merge sort that does not have to reverse every substack after sorting it, and it allocates the two auxiliary stacks only once prior to the ...
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1answer
63 views

Mergesorting a stack in Java

(See the next iteration.) I have this small program for sorting a stack using mergesort. Basically, the aim was to use as little aid from JDK library as possible. See what I have: StackMergesort....
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1answer
58 views

How to make doubly linked list design more efficient?

I have played recently and implemented doubly linked list with merge sort algorithm. I was wondering if there is any way of improving the algorithm further to make it as fast as possible (I know about ...
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66 views

Java merge sort implementation

Is this a good implementation? ...
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1answer
76 views

Creating a count inversion array of an unsorted array of unique integers

Given an array: arr = [2,3,1,4] I could write a count inversion array such that counting all numbers n2 after a certain ...
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1answer
54 views

Merge sort implementation efficiency

I made a merge sort implementation in C++, which I have tested with the values: 6, 38, 27, 7, 12, 58, 92, 43, 3, 9, 82, 10 producing the correct output of: <...
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1answer
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Parallel merge sort in Java

I have rolled my own parallel merge sort. My performance figures are as follows: Seed: 1457521330571 java.util.Arrays.sort() in 6840 ms. Sorted: true java.util.Arrays.parallelSort() 3777 ms. Sorted:...
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Natural merge sort in C

I have this C implementation of the natural merge sort: ...
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114 views

Slow merge sort

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Implementation of merge sort in Python

I was working on an assignment and I was hoping to know if the merge sort algorithm I wrote in Python was not making any unnecessary computations. ...
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4answers
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Implementation of mergesort in C

I have implemented mergesort in C. Any advice on making it more compact? My merge function seems less than fully optimal. ...
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2answers
176 views

String merge sort in Java

This snippet is about sorting a set of strings using merge sort. However, this version is tailored for strings as it relies on lcp values: Given two strings \$A\$ ...
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Counting inversions in C++ via mergesort and vectors [closed]

I have a text file that contains 100,000 numbers from 1 ~ 100,000 in an unsorted manner (no duplicates). The name of the file is "IntegerArray.txt" My task is to count the number of inversions in ...
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1answer
83 views

Constructing an odd-even mergesort sorting network

I was searching for a non-recursive odd-even mergesort implementation and found this one: Sedgewick R. The resulting sorting network is not an odd-even-merge sort network. When one draws a diagram ...
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1answer
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Natural merge sort in Java - follow-up 3

(See the previous iteration.) Now I have optimized my natural merge sort: Suppose the input sequence is $$\langle 2, 1, 4, 3, 6, 5, \dots, n, n - 1 \rangle.$$ My previous iterations would degrade ...
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211 views

Merge two sorted linked lists without recursion

Is this an effective way for merging two lists? It seemed too long. struct Node { int item; Node *next; }; Method: ...
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1answer
58 views

Merge sort in Clojure

I made my own version of merge sort: ...
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3answers
100 views

Mergesort performance in C

I have two questions about my code: Are there any performance improvements in this implementation or generally (register int ?) that I could make? What could I ...
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1answer
120 views

Mergesort in C++

I'm flexing the C++ muscle and came up with the following implementation of Mergesort. Any suggestions as to the implementation and style are welcome. ...
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2answers
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Run-aware merge sort

The concept is very, very simple: let's do merging run by run (a run is a range without decrement). ...
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Parallel Merge Sort in Scala

I have been trying to implement parallel merge sort in Scala. My current implementation is about as fast as .sorted, but I have no idea what would be the right ...
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Merge two list and discarding duplicates

I am trying to implement a function that merges two ordered lists into a third (ordered) one, but duplicates have to be discarded (basically the last step of a mergesort). I think that this code can ...
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C++ implementation of merge sort

I am studying the merge sort algorithm and implemented it. In the mergeSort function, I am allocating two new vectors. Can I do it without allocating extra memory? ...
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1answer
117 views

Merge Sort - Using Ruby and Recursion

I am implementing the algorithms of Course: Coursera Algorithm I. I implemented the Merge-Sort using recursion and although it sorts correctly I am not sure if it is a correct implementation of this ...
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0answers
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Natural merge sort in Java - follow-up 2

See the the previous iteration. Now I refactored the code a bit so that I do not need to pass like 6 parameters to helper methods. Also, I did a small tweak that allows the sort to arrive to the ...
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2answers
361 views

Bottom up mergesort in C++

See the next iteration. I have this C++ implementation of bottom-up mergesort (mergesort using iteration instead of recursion): bottom_up_mergesort.h: ...
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Takes in two sorted lists and outputs a sorted list that is their union

Write a function that takes in two sorted lists and outputs a sorted list that is their union Could anyone help me to improve this code and make it more user-friendly? We are not supposed to use ...
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2answers
192 views

Merge Sort without pointers in C

As part of an online course exercise, I was supposed to implement Merge Sort in C. Pointers were still not discussed prior to this exercise, so I have to work with arrays. Memory efficiency is not ...
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1answer
57 views

Another Scheme Mergesort

Here's a merge sort I wrote trying to learn Scheme. ...
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1answer
507 views

Sorting a linked list using mergesort

This sorts a linked list using mergegort. Can you please critique my code and provide your thoughts on where I should improve my code? ...
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1answer
87 views

Bottom up mergesort - singly linked list

I have written the following program in Go to mergesort a singly linked list. It does bottom up merge sort and hence does not have to find the mid of the linked list. Please review the algorithm and ...
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2answers
66 views

Mergesort through recursion

Could someone kindly have a look at the recursive merge sort below and let me know if there are any improvements? I'm mainly interested in either improving the code speed or making the code shorter. <...
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1answer
229 views

Counting number of inversions

This is a HackerEarth Challenge Problem. Question: Puchi hates to carry luggage, but unfortunately he got a job to carry the luggage of his N friends in office. Each day, one of his N ...
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1answer
204 views

Bottom up mergesort in Java

See the next iteration. I have this iterative mergesort (a.k.a. bottom-up mergesort). BottomUpMergesort.java: ...
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944 views

The stocks problem - find the biggest profit that can be made

The Stocks Problem: Given an array of n integers representing the price of a stock over the course of n days, determine the maximum profit you can make if you can buy and sell exactly 1 stock over ...
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2answers
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Beginner implementation of Merge Sort

This is my first time implementing a merge sort (just getting started with algorithms & data structures). Are there any obvious things I have done wrong? I am also worried that I have overused ...
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2answers
294 views

Merge Sort in Perl

I'm new to Perl and have successfully written a merge sort program. I'll paste the entire program below, but would like mostly a review of the subroutines ...
5
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1answer
355 views

Merge sort implementation in JS

Just for learning and practicing I've created a completely recursive version of the merge sort algorithm. I've tested it a little bit and it seems working, but I'm quite sure that it can be largely ...
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2answers
207 views

Merge Sort algorithm

I just read and experimented with C++ implementation of the merge sort algorithm from the Wikipedia page. During the experiments I have slightly modified the source code and would like to know how ...
5
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2answers
387 views

Merging sorted arrays

I'd like to know if it's ok to write like this or there is a better, prettier way to do this. The merging itself is ok. I'm more interested in dealing with the situation when one of the arrays is ...
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2answers
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Modern, C++ compliant, merge sort

This is a kind of follow up to my previous sort implementation review with specific questions to merge sort, and Modern C++ idioms. ...