Recursion in computer science is a method of problem solving where the solution to a problem depends on solutions to smaller instances of the same problem.
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Get all combination of a nested object with arbitrary levels in javascript
I have a JSON data which can be an Object/Array of recursively nested object or array. The value of an array can not be null, but an value in a object can be null.
And I would like to return all ...
2
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2answers
39 views
Remove all occurrences of a digit from a number
I need to remove all occurrences of a digit from a number in a recursive function with this prototype:
unsigned rem(unsigned num, unsigned dig);
This is my ...
4
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3answers
83 views
Recursive methods of singly linked list
Can anyone review the methods? If there are better ways to write a certain method I would appreciate it if anyone could tell me.
...
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0answers
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Recursive insert method for a singly linked list [on hold]
I've been trying to write recursively various methods on a singly linked list. Here's the insert method where I have to insert an element at a specific index (not at the end). Here's what I've ...
5
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2answers
96 views
BF interpreter in Python that uses recursion to handle loops
I wrote a Brainfuck interpreter in Python and I'm wondering how to simplify it.
I handle separately loop commands and the others. A recursive function deals with loops.
...
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2answers
50 views
Traversing javascript/json based on a dot-separated lookup string
I have an object of arbitrary depth, and a string (or array) containing the keys which have to be traversed to get to the value.
As far as I know, there's no method to get to the value directly:
...
2
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1answer
41 views
Counting occurrences of “hi” in a string, except where followed by “x”
I already solved this one from CodingBat, but I'm unsatisfied with my solution and I feel I could have made it much shorter. Most of the other recursion tasks could be solved by a one line conditional ...
2
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2answers
79 views
Integer to English challenge
I have a challenge, which is to create a JavaScript function that turns a given number into the string representation. For example:
console.log(inToEnglish(15)) ...
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0answers
48 views
Hierarchical Data to Graph
I am using vis.js to visualize some hierarchical data. I have created a recursive routine to add nodes and edges for each group and value in the dataset.
I feel like something already exists for this ...
2
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1answer
18 views
Liquid navigation tree generator
This include was written for a Jekyll site I'm building. It generates nested HTML unordered lists to a given depth dynamically by parsing page urls. It works fine, but the code feels messy and it ...
5
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2answers
132 views
Java 8 Stream to produce all permutations of an array using recursion
I want to write a class that returns a Stream of permutations of an int[].
...
3
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4answers
98 views
Copying file dependencies
I have written the following code, and it works great, but I'm not satisfied. I really love the book "Clean Code" by Uncle Bob and I try to apply all his principles when coding, but I'm having a tough ...
2
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1answer
70 views
Object-to-array flattening function
I have written a function that is designed to convert an object into an array of key/pair values ("flattening it") like so:
Input
...
2
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1answer
63 views
Find all distinct subsets that sum to a given number
The function wants to achieve to find all distinct subsets that sum up to an given number.
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3
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1answer
33 views
Find zeroes in a matrix
I am looking for the elements that are zeroes in a square matrix (of size n), as a list of pair. I don't really like the following code, some condition seems ...
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0answers
25 views
Recursion into git diff tree using nodegit
I'm using nodegit to develop the backend for a nodejs app that uses a mix of mongodb and git for persistence. The app has to version documents and be able to present diffs between versions, thus the ...
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0answers
55 views
Finding a Cartesian product of multiple lists
I came up with an extension method to find a Cartesian product of multiple IEnumerable sets. I was able to achieve lazy enumeration via ...
0
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0answers
28 views
Show products in dropdown from parent to chid
My goal is a list selector like this:
To do this I wrote these methods:
First:
...
3
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1answer
49 views
SICP - exercise 1.11 - tree recursion
From SICP
Exercise 1.11: A function \$f\$ is defined by the rule that:
\$f(n) = n\$ if \$n < 3\$, and
\$f(n) = f(n-1)+2f(n-2)+3f(n-3)\$ if \$n >= 3\$.
Write a procedure ...
5
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1answer
93 views
Finding ways to achieve a target sum using recursion
I need your review and suggestions how to make this code better. I'm just learning recursion and sure that this solution is not ideal.
Question:
Write a function that given an input array of ...
2
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2answers
42 views
Computing the largest substring starting with a substring
Given a string and a non-empty substring sub, compute recursively the largest substring which starts and ends with sub and return its length.
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3
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1answer
40 views
Recursive function to copy over an object with very specific constraints
I totally suck at recursion. I have a function that works but it also looks horribly wrong. I would love to 1) Know how to write it properly 2) Know about resources to read/study so that I don't get ...
2
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0answers
22 views
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1answer
20 views
Binary Search Tree insert while keeping track of parent for node to be added - iteration 2
Follow up question to
Binary Search Tree insert while keeping track of parent for node to be added
I am implementing a red black tree for fun and am wondering how I should modify my basic BST ...
0
votes
1answer
24 views
Binary Search Tree insert while keeping track of parent for node to be added
This question has a follow up question:
Binary Search Tree insert while keeping track of parent for node to be added - iteration 2
I am implementing a red black tree for fun and am wondering ...
3
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1answer
116 views
Tail-recursive call vs looping for a Poker app
I'm developing a Poker app. It is almost done, and I'm looking for improvement. One of the things I wonder is whether I should change how I perform iterations. I currently iterate by using ...
2
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1answer
45 views
Basic JSON Representation in Rust
This week I started reading "The Rust Programming Language". As I reached the chapters on enumerations and pattern matching I felt I had enough material to put together a simple representation of JSON ...
5
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2answers
48 views
Making the same amount from different combinations of coins (top-down approach)
I was reading a typical interview question found here. Given an amount and a list of denominations, count the number of possible ...
2
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0answers
54 views
Generate Subsets Of K Elements From A Set Of Strings
This is the task:
Write a recursive program, which prints all subsets of a given set of N words.
Example input:
words = {'test', 'rock', 'fun'}
...
2
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1answer
73 views
Recursive function application
I use a lot T4 templates and want to avoid extra code writing when it could be generated. Currently I have following class:
...
2
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1answer
46 views
Reversing all nested sequences
I'm writing a function that returns all (nested) sequences reversed:
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2
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1answer
77 views
Find all the countries I can visit by just crossing direct borders
I was helping on this question. There you have a table border to indicate countryA and countryB have a common border. And want ...
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1answer
65 views
Recursive function in JS
EDIT:
The code i provide includes a asynchron task in each interation, therefor i need the recursive function, my question is how to beautify the code and apply the proper use.
I want to:
Remove ...
6
votes
2answers
62 views
Perl recursive copy and move functions
I know a module like this already exists on CPAN, but I wanted to write my own simplified version that accepts wildcards in the input.
I don't write many Perl modules so I figured I would post the ...
4
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2answers
105 views
Given a path to a directory, print the path to the biggest file in it
Here is my code. I simulated a stack rather than used some regular recursive algorithm because I needed to keep track of two variables: the path to the biggest file and its size. Besides I wrote a few ...
7
votes
1answer
176 views
Path finding algorithm using recursion in Python
Here is a code I developed some time ago. I wonder if there is anything I can do to improve it. It works for non-loopy mazes which was already my goal.
In the maze defined, ...
2
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1answer
33 views
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4answers
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1answer
87 views
Recursive program for generating and printing all permutations of the numbers 1, 2, …, n for given integer number n
I've just written code for generating all permutations of the numbers from 1 to n in Java. It seems to work, but I think it's a bit more complex than it needs to be.
...
6
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1answer
66 views
Pick sequences of numbers to maximize the points
It is a single-player game. In the beginning, there is a row of integers. In one move the player can take a certain amount of adjacent numbers (let's denote it T). Then the player's points increase ...
7
votes
3answers
695 views
Check if 2 arrays have (exactly) the same elements recursively
I've been given a homework assignment to make a function to check whether 2 given arrays with the same given size have exactly the same set of elements.
My function seems to be working but I feel ...
-7
votes
1answer
65 views
Counting number of steps while finding right path [closed]
I am writing a code which would return the path in a maze using recursion, but now with the path I also want the number of steps.
How do count number of steps in this program? or number of times ...
2
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0answers
41 views
Recursive implementation of integer partition without re-arrangement
Problem: Integer partition without re-arrangement
Input: An arrangement S of nonnegative numbers {s1, . . . , sn} and an ...
4
votes
4answers
122 views
Finding the max sequence finder
Problem Statement
Find the max sequence finder.
findMaxSequence([3, 2, 3, 4, 2, 2, 4]);
...
3
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0answers
41 views
Recurse on complex Perl data structure, applying needed rules
Inspired by this answer and previous a commentator of code review use:
Given a complex Perl data structure, traverse/jigger/modify as follows:
If ORACLE_SID is ...
17
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4answers
4k views
Print the Twelve Days of Christmas without loops or conditionals
For my AP Computer Science class, I am required to write a program that prints the Twelve Days of Christmas without loops or conditionals using static methods.
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4
votes
3answers
112 views
A “map” function that alternates between two mapping functions
I am trying to solve following problem in Haskell using recursion:
Define a recursive function funkyMap :: (a -> b) -> (a -> b) -> [a] -> [b] ...
2
votes
2answers
118 views
Code optimization of recursive function
I have a mathematical function as shown below
$$ (h+1) * U(k,h) = \sum_{r=0}^k \sum_{s=0}^h (r + 1) * (k - r + 1) *
U(r + 1, h - s) * U(k - r + 1, s)\ + \sum_{r=0}^k \sum_{s=0}^h (k - r
+ 1) * ...
6
votes
2answers
106 views
A recursive program that attempts to solve an extremely large number
This is my recursive program for the following function:
\$F(x) = G(x) - W(x)\$
\$G(x) = [G(x-1)+G(x-2)]^2\$
\$W(x) = [W(x-1)]^2 + [W(x-2)]^2\$
If x == 0 in either function G or function W, then ...
6
votes
1answer
91 views
Function that recursively downloads entire directory is slow
I created this function to recursively copy an entire directory from an FTP server. It works just fine except that it is about 4 times slower than using FileZilla to do the same operation. It takes ...
