All Questions
18 questions
3votes
1answer
319views
Efficiently calculate value of Pascal's Triangle using memoization and recursion
So reading about functional programming, applications to dynamic programming, and learning Scala. I figured I would try it out with a popular example, Pascal's Triangle, tests against known values ...
- 133
2votes
0answers
187views
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 ...
- 121
1vote
1answer
121views
Find first repeating Char in String
Given a string, find the first repeating character in it. Examples: firstUnique("Vikrant") → None ...
- 405
4votes
2answers
450views
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 ...
- 405
1vote
1answer
99views
Check if list contains a pair which adds up to a given sum
Kindly review this scala code for given problem and suggest improvements. Problem - Given an array of integers and a target sum, check if array contains a pair which adds up to sum. Example - <...
- 405
5votes
1answer
249views
Bowling game Kata in Scala - pattern match
This is a functional approach to problem described by standard Bowling Game Kata - to implement the rules of calculating a score in a bowling game. The inspiration was the implementation by Uncle Bob: ...
0votes
1answer
2kviews
Cartesian product in Scala
I'm using this code to compute a cartesian product: ...
2votes
1answer
100views
Building and querying an immutable phone book
I wanted to get your opinion on this immutable implementation of a Phone Book using recursion to process a stream. I am especially interested in ways to speed up the code execution. Here is an ...
- 123
0votes
2answers
1kviews
Recursive Scala Case class Reduction
I have a case class that is recursive and looks like this: ...
- 103
2votes
1answer
105views
Selecting subset of size k using recursion [closed]
Sometimes I need to implement recursive algorithms that pass a certain state from one recursive call to another. For example, a greedy subset selection: we have a set of candidate objects, and we ...
- 37
2votes
3answers
1kviews
Tail-Recursion to get a Map of word counts
I want to read a file and store the number of occurrences of each word in a Map, using tail recursion. I came up with the following; it seems to work; does it look like it's right? ...
3votes
3answers
131views
Removing nested blocks from a string
I wrote this function in scala that uses tail recursion to remove nested blocks from a text. Usage examples: ...
3votes
3answers
3kviews
Pascal triangle algorithm is good but fails
I have created a function which returns the number that corresponds to the given row and column from the pascal triangle. I have used the formula for this: n! / r! * (r-n)! The code: ...
- 369
10votes
5answers
22kviews
Pair matching elements from two lists
Here is a method that takes two lists (l1 and l2) and pairs up elements that "match". As you can see at the end of the code ...
4votes
1answer
3kviews
Recursive branch and bound Knapsack solution [closed]
I've got the imperative styled solution working perfectly. What I'm wondering is how to make a recursive branch and bound. This is my code below. Evaluate function returns the optimistic estimate, ...
- 143
