All Questions
35 questions
2
votes
3
answers
553
views
Recursive palindrome check
I'm trying to solve this which basically calls for a recursive palindrome check with some minor extra steps (Special characters and whitespace can be ignored). The test inputs' length can be 100000 ...
6
votes
3
answers
2k
views
Money change exam
I was asked to create a method that would:
Return a Change object or null if there was no possible change
The "machine" has unlimited bills of: 2, 5 and 10
The Change object must return the ...
- 171
5
votes
1
answer
261
views
Drawing a Thue-Morse pattern recursively
This is web exercise 3.1.63. from the book Computer Science An Interdisciplinary Approach by Sedgewick & Wayne:
Write a program that reads in a command line input N and plots the
N-by-N Thue-...
- 1,363
5
votes
2
answers
493
views
How to optimize Karatsuba algorithm (using arraylist and java)
I was using Karatsuba algorithm to multiply two polynomials and return the coefficients and I am using java, we are asked to use arraylists here, however, my code is too complicated and it takes much ...
- 51
2
votes
1
answer
557
views
Speeding up a recursive Cantor pairing function
The Cantor Pairing function is a mathematical function which takes two integers and combines them into a single integer that is unique to that pair. This single integer can later be "unpaired" back ...
- 205
2
votes
2
answers
152
views
"Smart" sudoku brute-forcer
After running my C-brute-forcer for two days on a 25x25 sudoku, I decided to re-write in Java so that it would solve it in an acceptable time frame. The idea: Make smart fields that contain all ...
- 866
1
vote
1
answer
439
views
Rectangle packing in smallest possible area
I have written a Java Program to place a bunch of rectangles
into the smallest possible rectangluar area(no overlapping and rotating).
Here is a short summary:
I calculate minArea and maxArea:
...
- 595
4
votes
3
answers
1k
views
Java Magic square program
Here is my improved version of my Magic square program from following this earlier version.
I also added a few comments.
Any help for improvements would be really appreciated.
...
- 595
3
votes
1
answer
661
views
Speed up Magic square program
I have written a Java program to calculate magic squares with recursion and backtracking. A 3*3 Magic square is calculated in about 1 sec, but a 4*4 needs about 50 minutes on my laptop with Intel i5. ...
- 595
1
vote
1
answer
496
views
Counting contiguous subarrays with a negative sum
I'm doing a coding challenge that asks to count the number of contiguous subarrays that have a negative sum:
A subarray of an n-element array is an array composed from a contiguous block of the ...
- 171
1
vote
4
answers
2k
views
Improving Fibonacci recursion with BigIntegers
I've been tasked with making a fast Fibonacci recursive method that uses BigInteger to calculate REALLY big numbers. However, to calculate numbers past 30 it takes ...
- 13
2
votes
2
answers
3k
views
All possible groups of combinations of array
Let's assume I have a one-dimensional array of integers of size n. My problem is to generate all the combination of all possible groups of size 1 to n, such as each combination has exactly one ...
- 121
6
votes
2
answers
20k
views
Find all words in a dictionary that can be made with a string of characters (Recursion/Binary Search)
I'm working on an algorithm that could take in a string of 20 random characters, and display to the user every word in a dictionary that can be successfully made with those letters, regardless of ...
4
votes
1
answer
2k
views
Pizza ordering program recursion on the GUI
This program is a basic pizza ordering program with seven topping options, four size options, and five crust options. It pulls the options from a database and populates the GUI on start.
I connected ...
- 127
3
votes
2
answers
342
views
Java exhaustive solution
This is a take on Pebble Solitaire. The user inputs n number of games and after that inputs a strings of length 23 that contains a combinations of only 'o' (pebble) and '-' (empty space). If there are ...
- 31