All Questions
Tagged with java performance
1,280
questions
2
votes
2
answers
63
views
A thread-safe performant Money Transfer API in Java
This is a popular interview question. It is meant to be done within 30 minutes. The task is to implement a thread-safe performant Bank Account API that allows to transfer, deposit, withdraw and check ...
3
votes
1
answer
217
views
Leetcode: Number of Islands - BFS (Queue vs Recursion)
I was playing around with leetcode's Number of Islands.
As per the challenge's description:
Given an m x n 2D binary grid grid which represents a map of '1's
(land) and '0's (water), return the ...
5
votes
1
answer
121
views
Creating random music covers using Conways Game of Life algorithm
(A sample cover art follows.)
I'm currently working on replacing all the covers of my music files to have a unified theme, and I've started this project in Java to refresh my knowledge after a gap of ...
5
votes
1
answer
332
views
Leetcode: Largest Number
I was trying out leetcode's Largest Number.
As per the challenge's description:
Given a list of non-negative integers nums, arrange them such that
they form the largest number and return it. Since ...
4
votes
2
answers
492
views
Leetcode: Steps to Make Array Non-decreasing
I was trying out leetcode's Steps to Make Array Non-decreasing
As per the challenge's description:
You are given a 0-indexed integer array nums. In one step, remove all
elements nums[i] where nums[i ...
9
votes
4
answers
2k
views
Leetcode : First Missing Positive
I was trying out leetcode's first missing positive.
As per the challenge's description:
Given an unsorted integer array nums, return the smallest missing
positive integer.
You must implement an ...
1
vote
1
answer
368
views
Inserting large number of rows into database with Spring boot
I need to insert many million rows + many GB of data into a database for a project that uses Spring boot. I recreated a minimal example with a one to many relationship and am trying to find the ...
6
votes
3
answers
698
views
Program that brute forces to find the minimum dominating set
This program solves the minimum dominating set but it takes an insanely long time to run. In case you do not know, in graph theory, a dominating set for a graph G is a subset D of its vertices, such ...
4
votes
2
answers
427
views
Map constructor utility class in Java 8
In a Java 8 project, I'm using several maps, many of which contain static or default content. In Java 9 and newer, there's the convenient Map.of() method and I want ...
2
votes
4
answers
177
views
Comparison of two excel files ignoring line order
Below is a simple method which compares contents of two excel files ignoring the line order.
This method is working as expected.
But, one of my peers in their code review mentioned that initializing ...
2
votes
1
answer
78
views
Implementing an improved merge sort that uses insertion sort, with "levels" - Would this work correctly?
We were asked to improve the merge sort algorithm by introducing insertion sort to the code. We have been tasked with doing this by utilising a "levels" logic. Here is the exact description ...
6
votes
1
answer
125
views
One or more planets to line up with the earth a certain amount of times
I have attempted the below question, however my solution is too slow (i.e. It does not fit the 2 second time constrain for java). How can the solution be optimised?
While at IOI 2020 in Singapore, ...
3
votes
1
answer
93
views
Performance of this BCrypt lossless compressor
The following code compresses a 60-byte BCrypt MCF into 40 bytes.
Does anyone see room for performance or other optimizations?
For example, I should replace Guava's ...
0
votes
4
answers
119
views
Code counts the number of identical elements between the arrays 's' and 'd' at the same index
I wrote a code and the code counts the number of identical elements between the arrays s and d at the same index. I need to ...
1
vote
0
answers
73
views
A parallel MSD radix sort in Java for integer keys
I have this repository: https://github.com/coderodde/ParallelRadixSort.java/tree/main
It contains a parallel MSD radix sort presented below:
...