Questions tagged [scala]

Scala is a general purpose programming language principally targeting the Java Virtual Machine. Designed to express common programming patterns in a concise, elegant, and type-safe way, it fuses both imperative and functional programming styles.

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28 views

Rewriting scala code in object-oriented style style to reduce repetitive use of similar functions

I need help in rewriting my code to be less repetitive. I am used to coding procedural and not object-oriented. My scala program is for Databricks. how would you combine cmd 3 and 5 together? Does ...
5
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1answer
108 views

Improving my Tic Tac Toe Solution in Scala

I'm relatively new to Scala and made a small TicTacToe in a functional Style. Any improvement options would be highly appreciated. There are some things which I am unsure of if they are made in an ...
3
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1answer
88 views

Improvements, TicTacToe in Scala

I've just started my journey into functional programming and tried to implement a TicTacToe game Recursively without State in Scala. What I dislike is the JOptionPane but I don't know if i can solve ...
4
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1answer
36 views

Convolution function

I implemented the following function using the matrix object from breeze library. Basically it is just a glorified while loop. The convolution there is extremely ...
2
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1answer
40 views

argmax of List of Double

Here is my implementation of arg max in Scala. q_table_test.txt contains: ...
2
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0answers
85 views

Spark Scala: SQL rlike vs Custom UDF

I've a scenario where 10K+ regular expressions are stored in a table along with various other columns and this needs to be joined against an incoming dataset. Initially I was using "spark sql rlike" ...
3
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2answers
61 views

Compressing string in Scala, how to do this immutably?

I have a string "abbbbccdddd" and the function should return "a1b4c2d4". This is what I have written in Scala. Iterative-version ...
3
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1answer
35 views

Scala code to insert a row into Hbase

Below is a case class and a companion object with a method putRecord which adds a new row into Hbase using Put API. This code has some repetitive parts. Is there a ...
3
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1answer
65 views

How to make it more Scala compatible?

When you write a code in python code people always ask to make it more pythonic. I am not sure if there is a term for scala or not. However, I am pretty sure my following code use one or two scala ...
3
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1answer
45 views

Scala: Cumulative String Tokenisation

I'm trying to split an incoming stream of strings into cumulative tokens per line item using a function below, ...
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2answers
48 views

A better OOP way for solution

I am implementing a functionality in Scala to Copy files from one FileSystem to another ...
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0answers
40 views

how should I optimise the scala code and make it more readable

I have this ugly massive piece of code. It does many things, mostly around querying databases. Each query depends on the result of the previous query or on the parameters of the incoming request body. ...
4
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1answer
81 views

A simple data class based on an existing collection (Scala)

I'm fairly new to Scala and I would like to learn it properly. My current task is to create a type to represent a heap, as seen in interpreters: a mapping from addresses in memory to values stored ...
2
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1answer
62 views

What is better to use for mapping value to Map of functions: tail recursion or foreach?

I want to map functions from my functions library (Map called as chain) to input string str. ...
4
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1answer
67 views

Clean up tags from a text

I need to generate random text for tests. I do that using alphanumeric characters and some special characters as well. For some special cases, I cannot generate the random text with tags. I have the ...
2
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1answer
78 views

Integrating caliban, ZIO and Akka

I created a small sample project using caliban, akka-persistence and ZIO. I'm not really happy with the wiring code: ...
0
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1answer
45 views

implementation of atoi in scala

I've implemented atoi function as described in leetcode problem string-to-integer-atoi. I am looking for some feedback on writing this in a more scala native way ...
2
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0answers
149 views

generic implementation approaches for a recursive function

Let's take the famous fibonacci problem as an example but this is a generic problem. Also, taking scala as the language as it's rather feature-rich. I want to know which solution you'd prefer. we all ...
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1answer
55 views

Scala graph coloring

i have solved this problem https://leetcode.com/problems/find-eventual-safe-states/submissions/ ...
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0answers
38 views

Finite automaton library in Scala including subset construction and minimization

I built a scanner generator like flex or jflex in Scala for a class last year. Part of this project is a small library for handling and manipulating finite automata. It works completely as intended, ...
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1answer
54 views

Functional filter unique elements in sequence is not as good as imperative [closed]

Can you please help me fulfill the following? Requirements: Create an iterable with unique elements. Their order should be preserved: a | b | a | c → a | b | c ...
2
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0answers
92 views

Bellman-Ford Implementation in Scala/Java

I think the part to get shortest path from the cost table got pretty messy. Also can use some tips on how to avoid the extra O(V+E) work checking all edges from source to dest after getting the cost ...
1
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1answer
284 views

Perfect Number usage in higher order function

I am new to Scala. I have been trying to complete an exercise where the ask was as follows: // Write a function isPerfectNumber which takes integer input and returns String output. // It finds if a ...
2
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0answers
77 views

Synchronous use of Mongo-Scala Driver

The Mongo-Scala Driver (v2.6) currently only supports asynchronous operations, although my use cases often seem to lend themselves well to synchronous reads. This may be to block downstream code ...
3
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1answer
374 views

Dotty 0.19 (Scala 3) features: contextual abstractions

tl;dr I tried to write some as general and as feasible as possible code where entities are able to communicate with other entities of the same type or of different types, allowing for the recipient ...
2
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2answers
285 views

Scala app to transpose columns into rows

This is the first application or really any Scala I have every written. So far it functions as I would hope it would. I just found this community and would love some peer review of possible ...
1
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1answer
73 views

Create JIRA ticket using REST API

Objective: The objective of the program is to create a JIRA ticket using a REST API. It's working perfectly fine without any issue. However I am not sure if it's up to good Scala standards. I would ...
2
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1answer
142 views

Return all anagrams for a word matched against a list of words in a file

The exercise description: Given a ‘words.txt’ file (attached) containing a newline-delimited list of dictionary words, please implement a small command line application capable to return all ...
3
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1answer
60 views

Counting bigrams in XML files in a directory tree

I've written this code in Scala that extracts bigram statistics from the Reuters dataset. It puts the statistics in a Map[String, SortedMap[String, Int]]. For ...
0
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1answer
90 views

Provide functional-programming style solution for 2D Array - DS challenge

Problem Statement: Given a 6×6 2D Array, arr: 1 1 1 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 We define an hourglass in A to be ...
0
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1answer
156 views

Imperative and functional-programming solutions for Jumping on the Cloud challenge

Problem Statement Emma is playing a new mobile game that starts with consecutively numbered clouds. Some of the clouds are thunderheads and others are cumulus. She can jump on any cumulus cloud ...
3
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2answers
205 views

Count character 'a' in first n characters of indefinitely repeating string s

Problem statement: Lilah has a string, s, of lowercase English letters that she repeated infinitely many times. Given an integer, n, find and print the number of letter a's in the first n ...
4
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2answers
169 views

Counting valleys traversed below sea level, given elevation changes

Problem Statement: Gary is an avid hiker. He tracks his hikes meticulously, paying close attention to small details like topography. During his last hike he took exactly steps. For every step ...
4
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1answer
73 views

Print a Connect 4 grid based on some rules for each cell

In a game of Connect4: we start with an empty grid two players place pieces X and O on the grid the first player to achieve 4 pieces in a line wins! this is a text based console game Here is the ...
-1
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1answer
49 views

Perform KS-test on Random Number Generator [closed]

I've just started practicing Functional Programming in Scala in some days. This is the code I used to perform KS-test on a random number generator. ...
0
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1answer
64 views

Is it possible to DRY these 2 methods of a tailrec Node Tree?

I have a Tree structure composed by Node class. I have to @tailrec method that are visiting up to the root. Those 2 methods ...
3
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3answers
151 views

Computing average duration per user from a large CSV file that doesn't fit in memory

We have a large log file which stores user interactions with an application. The entries in the log file follow the following schema: {userId, timestamp, actionType} where actionType is one of two ...
5
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1answer
615 views

Extracting numeric values from a string containing key:value pairs

I am writing function numericValues(text: String): List[Int] to extract patterns """([a-z]+)\s*:\s*(\d+)""" and return the list ...
1
vote
1answer
42 views

Page download with reattempts in Scala

I wrote the following code to deal with possible network problems. ...
3
votes
2answers
104 views

Solve membership binary mask problem in Scala

Imagine you have two string sequences: val s1 = Seq("c", "a", "b", "z", "a", "b") val s2 = Seq("a", "b") You need to come up with an algorithm that generates a ...
1
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0answers
97 views

Java classes to load configuration data from a JSON file, with Scala tests

I want to implement classes in a project that will support the loading of configuration data from a JSON file. The JSON file is in the following form. Please be as critical as you can be. I'm a junior ...
1
vote
2answers
82 views

Count Substrings for a binary string

Problem is taken from leet code. Give a string s, count the number of non-empty (contiguous) substrings that have the same number of 0's and 1's, and all the 0's and all the 1's in these substrings ...
1
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0answers
146 views

KMP algorithm in scala

I implemented KMP pattern matching algorithm in Scala. My code works but it looks more imperative and a scala translation of C/C++ implementation. I am not able to figure out how to manage multiple ...
0
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1answer
83 views

Find first repeating Char in String

Given a string, find the first repeating character in it. Examples: firstUnique("Vikrant")None ...
0
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2answers
47 views

Expand spreadsheet ranges to lists of cells in Scala

Problem Spreadsheet cells are referenced by column and row identifiers. Columns are labeled with alphabetical characters, starting with "A", "B", "C", ...; rows are numbered from 1 in ascending ...
1
vote
1answer
110 views

Minimum steps to reach target by a Knight In Scala

Given a chessboard of N size (square matrix), the position of Knight and position of a target, find out minimum steps (both count and exact steps) from start to target for a Knight. If it is not ...
1
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0answers
74 views

Closest 3Sum in Scala

This question is taken from Leet code. Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three ...
4
votes
2answers
108 views

Replace array element with multiplication of neighbors in Scala

Given an array of integers, update the index with multiplication of previous and next integers, Input: 2 , 3, 4, 5, 6 Output: 2*3, 2*4, 3*5, 4*6, 5*6 Following ...
0
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1answer
333 views

Clockwise rotate a matrix in Scala

Given a matrix, clockwise rotate elements in it. Examples: ...
1
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2answers
255 views

Print matrix in spiral order in Scala

Problem: Given a square or rectangular matrix, print its element in spiral order. For example, if input matrix is this: ...

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