Tagged Questions
Java (not to be confused with JavaScript) is a class-based, object-oriented, strongly typed, reflective language and run-time environment (JRE). Java programs are compiled to byte-code and run in a virtual machine (JVM) enabling a "write once, run anywhere" (WORA) methodology.
2
votes
2answers
46 views
Let me fix thou number
Problem Statement:
Write a program that cleans up user-entered phone numbers so that they
can be sent SMS messages.
The rules are as follows:
If the phone number is less than 10 ...
6
votes
0answers
32 views
Game Tutorial in Java
I’ve been working on a Rampart inspired multiplayer game for a few weeks now, and it is finally in a playable state. The big thing left to do before going alpha was to add a tutorial to the game.
I ...
4
votes
1answer
43 views
12/24h Time format converter
I am really new at this and I was wondering if there is a more efficient way of writing this code, which converts time format to 12-hour from 24-hour format, and vice-versa.
For example ...
-1
votes
0answers
25 views
Calculating a string using stacks, Not getting the right answer [on hold]
If someone doesn't mind could they take a look at my code? For some reason, I keep getting the wrong answer when the logic seems fine to me. Mainly the solve is what is probably wrong, but if needed I ...
1
vote
1answer
54 views
-6
votes
0answers
16 views
1
vote
2answers
52 views
Enum for converting between field naming conventions
Based on this question and this answer, I decided to try the enum approach to do some more conversions I need in my application. This time I required to convert between the different field naming ...
5
votes
1answer
40 views
Let's have a meetup
Problem statement:
Calculate the date of meetups.
Typically meetups happen on the same day of the week.
Examples are
the first Monday
the third Tuesday
the Wednesteenth
the ...
2
votes
0answers
24 views
Comparing linear time strongly connected component algorithms in Java
So I have implemented three linear time (\$\mathcal{O}(V + E)\$) algorithms for finding strongly connected components of a (directed) graph. A strongly connected component is just a maximal subset of ...
3
votes
4answers
243 views
Checking if String has unique values
I have a small function which checks if the given String has all 0's. This method would be used quite often and want to know if it's effectively written. Any help would be greatly appreciated.
...
2
votes
2answers
284 views
Clean Code: Improving readability and refactoring
I'm curious how I can improve the readability of this short program I wrote. Mainly if and how there is a way to remove the for loops and maybe refactor the ...
0
votes
1answer
25 views
Optimizing and accounting for edge cases in Dijkstra's algorithm
I just recently wrote a program to simulate how multicast routing works.
The program uses a weighted graph to represent the network and simply runs it through the algorithm.
I would like to know if ...
4
votes
1answer
73 views
Calculating running average in Java
I have a library which makes HTTP calls to my service. I was trying to calculate running average of how much time my service is taking on an average.
Here is the core logic of how I am calculating ...
-1
votes
0answers
14 views
Something is wrong with my infix to postfix conversion in JAVA [on hold]
I have been doing this for hours and checked other codes but when I implement them, the postfix is still not how it's supposed to be. It would be great if anyone could check them. Thank you so much
...
3
votes
1answer
32 views
Composite implementation of a prototype singleton registry
I am studying design patterns and I've implemented a composite prototype pattern which is also a singleton (one instance per JVM). The main and most important part of the code is the ...
11
votes
5answers
1k views
Generating Robot Name
Problem:
Write a program that manages robot factory settings.
When robots come off the factory floor, they have no name.
The first time you boot them up, a random name is generated, such ...
2
votes
1answer
27 views
Thread-safe Bloom Filter in Java
I have tried to implement a Bloom Filter in Java here.
https://github.com/srirammanoj/skynet/tree/master/bloomfilter
I just wanted to know if my implementation can be called 'thread-safe' , and if ...
2
votes
0answers
38 views
Final Java TicTacToe MVC Program
After my previous post, I decided to work on the project myself for a while (two weeks) to see how far I could get after reading a few of the really helpful answers to my previous posts. I read up on ...
1
vote
1answer
46 views
Mergesorting a stack in Java
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.java:
...
4
votes
2answers
113 views
Simple builder pattern implementation for building immutable objects
This is a builder pattern implementation to build immutable Person objects:
Person class
...
6
votes
1answer
64 views
Genetic algorithm to find the maximum binary number of a given length
I have written some codes in java implementing simplest genetic algorithm. The code finds (or rather tries to) the maximum value possible for a user-defined number of bits. For example, for 16 bit ...
1
vote
0answers
47 views
Updating many fields based on data from a web service
I have to receive data from a webservice and need to compare the received data with the data in our DB.
Its easy like: get a streetname from the WS, if its not null and not equals the Db entry -> ...
1
vote
0answers
17 views
Passive FTP port assignment synchronization
I've created the following class to manage the assignment of port numbers to passive FTP server sockets. Notice that Semaphore here is to make the thread wait in ...
1
vote
1answer
50 views
Java application processing GUI input when “Done” is clicked
Right now, I've got this really ugly loop in my code that waits for a boolean to be true before the method can return. It's triggered when "Done" is clicked. I'm ...
3
votes
2answers
33 views
Automatically keyed map
I have written a class that is designed to be an automatically keyed Map in Java.
Here is my implementation:
...
4
votes
0answers
53 views
Pseudo-parallel depth-first search
I'm writing a small program, that generates a file containing an adjancency matrix, it then reads from that file, constructs a graph and does something like a parallel dfs on it.
How can I make the ...
5
votes
0answers
44 views
Making a logic Prolog compiler simpler with Java
Good morning!
I'm student in philosophy taking some course in programing in order to have a better understanding of artificial intelligence.
I'm actually doing my own Prolog compiler just like SWISH ...
18
votes
3answers
3k views
What does the Bob say?
Description:
Bob is a lackadaisical teenager. In conversation, his responses are
very limited.
Bob answers 'Sure.' if you ask him a question.
He answers 'Whoa, chill out!' if you yell ...
4
votes
1answer
55 views
Sort a stack in descending order
Maintain current element as the top element in the input stack. Pop all the elements on the ordered stack which are greater than the current element and push them in to the input stack and maintain a ...
3
votes
2answers
74 views
ResourceManager class consisting of multiple singletons
I've implemented a class, which provides access to different static resources, which are used by different frontends. I'm hesitating, because in Java getters and setters are quite wide spread. So my ...
3
votes
3answers
82 views
Calculate the Hamming difference between two DNA strands
Write a program that can calculate the Hamming difference between two DNA strands.
GAGCCTACTAACGGGAT
CATCGTAATGACGGCCT
^ ^ ^ ^ ^ ^^
The Hamming distance between these two ...
2
votes
1answer
70 views
+50
AsyncTask method
Even I know that this isn't a good way of writing code, but I need to improve this.
Here I am retrieving data from Server in Json format by Posting some variables in doInbackground. Getting all the ...
2
votes
1answer
105 views
Searching two different elements in a same list
I have a list of conversion histories, where information about user channels is stored. For example user may have app for iOS and Android installed. Each time user logs in, I store a conversion ...
2
votes
0answers
38 views
Android login system
I am completely unaware of all the Android features and available libraries.
I just designed a login system to practice it. I have referred to a few books and tutorials.
Layout
I am using relative ...
1
vote
1answer
43 views
Implementing builder pattern In Java with a static inner and a Concrete standalone class
I am studying Gang Of Four design patterns and I want to implement a builder pattern in Java.
It seems there are two options to build a builder pattern:
Using two different classes: A target class ...
5
votes
4answers
117 views
Finding the longest sequence of positive numbers in integer array
I am preparing for a coding interview and I have the following questions:
Find the biggest positive number sequence in the Integer Array.
If Input is ...
3
votes
2answers
72 views
Parsing a string with named sections and a key-value pair on each line
I have a response String as shown below which I need to parse it and store it my class. Format is shown below:
task name followed by this dotted line ...
3
votes
0answers
23 views
Reader-writers problem using semaphores in Java
I have written my own solution to the Reader-Writers problems using semaphores based on the psuedocode from Wikipedia. I would like to gauge the correctness and quality of the code.
...
5
votes
6answers
332 views
Find maximum difference between values in an array
My task is to use the following pseudocode and improve it (make it run faster). Also I have to analyze the runtime of the given pseudocode and of my new code that i improved.
What does this algorithm ...
0
votes
0answers
41 views
Student information system using swing [closed]
Each student has roll, name and score as attributes. Add a method to
store the student objects in STUDENT.DAT file. Develop a GUI with a
query panel, output panel and a search button. In the ...
2
votes
3answers
143 views
Convert string to mixed case
This method converts a string to mixed case, id est mixedCase("hello, world!") -> "HeLlO, wOrLd!".
...
4
votes
2answers
54 views
Fraction class in Java - follow-up
(See the previous iteration.)
I have improved my Fraction implementation taking the answers in the previous iteration into account.
Differences
Both numerator ...
2
votes
1answer
33 views
Pen-and-Paper Dice Roller Tool
A friend asked me to write a pen-and-paper dice roller, so I put this together. I'm still pretty new to Java Swing, so I was hoping I could have some advice on how I handled the layouts and ...
5
votes
3answers
144 views
Interview coding test: Searcher
I did a task for an interview and the solution was not accepted. The task was to implement the class search function by name. The number of classes in the input data from 0 to 100000. Class names are ...
3
votes
1answer
44 views
Java Connect Four “Four in a row” detection algorithms
I am making a connect four type game for my end of the year project in my programming class. I am about to start building off of the console based version I have made and add a GUI, but I feel sort ...
5
votes
1answer
37 views
Three stacks in a single array
I have implemented three stacks in a single array in Java. Any advice on object oriented design, coding structure, logical part or any sort of advice would be appreciated.
...
3
votes
2answers
25 views
Thread Safe Servlet
I am working on a JSP MVC web application. I am confused about Thread-Safe Servlet concept. Following is my code, please tell me is it thread safe or not. Also, tell me the reason that why it is ...
0
votes
0answers
11 views
Getting data with Rxjava and retrofit
I am using rxjava with retrofit to get data from an api then filtering the data with for loop in the onNext Method. Is there anyway not to use the for loop and just use rxjava to filter or improve ...
4
votes
2answers
43 views
Counting from 0 to a number and back to zero, and space-padding the result to be a given length
I completed a task: The objective was to create a method with 2 arguments: a number to count to, and how many char/numbers in the resulting string.
Result: Let's say that "number" is 5, so it will ...
1
vote
1answer
33 views
