A data structure is a way of organizing data in a fashion that allows particular properties of that data to be queried and/or updated efficiently.

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Coupon collector

This is a coupon collector code to analyze the running time. I need some suggestions on improving the running times of this code. I have used the data structure dictionary, but is there any other data ...
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2answers
70 views

Inefficient hash map operation provokes OutOfMemory: Java heap space error

I know I can increase the size of the heap but that seems like a poor solution. This program runs correctly on small files but when run on large data sets it crashes with the OutOfMemory: Java heap ...
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3answers
375 views

Finding duplicates in two sorted arrays

This is an interview question from here. Specifically, the second asked for a function that took in two sorted arrays of integers with no duplicate values within a single array and which returned an ...
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2answers
96 views

Data structure to count occurrences of entries

I would love to hear any thoughtful suggestions on how to improve my programming style in order to be more understandable. Listed below is a sample of my code which I wrote in Eclipse: ...
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1answer
51 views

Design/reiterate or code reuse for linked list

This is what my class hierarchy looks like. I have an abstract superclass, AbstractLinkedMyList, that contains common operations for both sorted and unsorted linked ...
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1answer
246 views

Order a delicious pie here

For a quick summary: I've created this internal web application, and I've hit a point where I can really see the mess I've made. I need some help separating the logic, the view, and the data. More ...
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1answer
55 views

Rewriting linked list function without a NULL variable

This is how my LinkedList class looks like in PHP. I am trying to figure out if I can rewrite my reverse_list_recursively() ...
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3answers
72 views

Implementing a singly LinkedList and IList interface

I have implemented a LinkedList in C#. What would you change/make better? What naming conventions are misused? What would you add? Some of my ideas are to make it ...
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1answer
56 views

Finding the shortest substring containing keywords

Problem: Write a function that takes a String document and a String[] keywords and returns the smallest substring of ...
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4answers
448 views

Recursive binary search tree - follow-up

This is a follow-up to Recursive binary search tree changes: Used raw pointers rather than std::unique_ptr const correctness Made variable names more beautiful implemented at() How can I improve ...
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3answers
385 views

Preorder, inorder, postorder for tree in C++11

Please review my code for preorder, inorder and postorder of a tree. I am using C++11 (or wanted to use), so let me know if anything is deviating from the C++11 standard. ...
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0answers
40 views

Hash Table Implemented by Javascript

I recently tried to implement a simple hash table using Javascript. Could anyone help me review my implementation? ...
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2answers
87 views

Counting a cycle

An interview question I got - Each element of an int array points to the another element, eventually creating a cycle. Starting at ...
4
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1answer
59 views

Circular linked list in C

Let me know if it seems right to you and if anything can be optimized. My concern is that I'm unsure if circular linked lists are supposed to have a tail. I've implemented it just using a head. Is ...
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2answers
54 views

Doubly linked list code in C

Let me know if it seems right to you and if anything can be optimized. ...
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1answer
73 views

Circular queue implementation using two regions

Inspired by the "bip buffer", I coded a fixed-size circular queue that uses two regions (two pairs of begin/end pointers) to account for the wrap-around. The main goal of this design was to simplify ...
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0answers
58 views

Binary heap with O(1) lookup and O(log n) change key

I needed a priority queue that allowed efficient searching and changing of keys. I tried std::priority_queue, but the interface was extremely limiting. Not being ...
5
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2answers
96 views

Find if a word with wildcard exists in dictionary [closed]

This is a question from a phone interview I had. The question was in 2 parts: a. find("cat") -> T/F suggest a data structure to find is if a word exists in a large dictionary, how will one node ...
8
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1answer
91 views

Networking in iOS Swift

This piece of code is working - It gives me a lot of JSON back, which I have yet to parse, but I'd like to show my code here first to get tips on how to improve what I already have: ...
2
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1answer
137 views

Graph implementation adjacency list 1.0

Please note the following: All edges are directed Removal of edges/nodges is not implemented yet A user of the class Graph can never (hopefully) access a ...
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1answer
84 views

Find all the paths of tree that add to a input value

This code is attributed to Stack Overflow itself here. The path which adds to the sum, which need not be starting from the root, not be ending at the leaf, i.e. a path can be between root and a leaf. ...
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3answers
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Removing duplicates without using a temporary buffer

This question is from Cracking the Coding Interview and in this question they have asked to solve without using temporary buffer. I have used Iterator interface. Can I use it or need to re-implement ...
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2answers
83 views

Simple Linked Hash Map in JS (node/browser)

I needed a simple data structure to cache the most recent few directory contents for this project I was working on. I thought a Linked Hash Map would be the right approach since we will cache only one ...
6
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2answers
239 views

HashTable implementation

I have been trying to implement the Hash Table function in Java and here is what I came up with. I would just like to get an opinion on this work. Would there be a better way or any improvement to ...
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1answer
70 views

Implementing a stack using a simple array, dynamic array and linked list

I have implemented a stack using simple array, dynamic array and linked list. I am requesting a review of this code. Interface for stack: ...
3
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1answer
81 views

Deepest node in tree

I have written two classes, one to represent the tree and a Util class to get the deepest node from the tree. Can you please review the code? Below is the class ...
3
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1answer
58 views

AVL tree implementation in C

I have an assignment. I need to write an AVL tree. This is what I have written so far. It works on all of my tests, but suddenly fails in checking system with TL(time limit exceeded). Personally I ...
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3answers
171 views

Custom SkipList implementation in Java

I recently studied SkipList and thought i would create one on my own. This implementation uses a 2 layer Skip list where the size of the support list is roughly square root of the size of the original ...
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1answer
34 views

Manipulate JSON data from the client with JavaScript

I am making an application in which the user has the ability to add, remove, and edit JSON data through DOM interaction. I have created a working JavaScript-only prototype that accepts certain ...
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3answers
173 views

AVL tree for inserting and searching

I have made an AVL tree. It works and does what it needs to do. I only need it to insert and search. I am comparing how long it takes to load and search a dictionary file in relation to other various ...
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0answers
67 views

Djkistra shortest path implementation for adjacency list represented graph

Please review the implementation of Djkistra algorithms. Points on which I have doubt: My Graph doesn't have any ID for nodes. Nodes are accessed based on their ...
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1answer
90 views

School which registers students by preferred courses

The point of the application is to create a school, create courses for that school, create students and register them to the school, assigning them courses based off the courses they prefer. There ...
2
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1answer
75 views

File input and sorting averages with movies

So far I have Java code that will: take in two .csv files store each line as a string in a string array split it into a 2D string array where a comma would act as the separator sum the number found ...
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0answers
57 views

Treap with implicit keys

I implemented an implicit treap and tested it a little. It works fine but I'd like to know if there are ways to improve/simplify things and/or if some parts are incorrect. Later, I'll augment code to ...
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1answer
66 views

Pure fixed length queue

I am modeling an infectious disease with a fixed incubation period. I chose a queue to keep track of when people become symptomatic. I imagined using some operations like so: ...
11
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3answers
515 views

Implementation of an Stack without Linked Lists in C

I'm a beginning C programmer. As an exercise, I have attempted to implement a stack of strings in C. This is my first real exercise working with pointers. I looked at some other similar posts on here, ...
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0answers
62 views

Binary Index tree optimization

I have written code for binary index tree. My problem is there are many functions based on the binary index tree the function stores the sum of element within a given range of binary index tree and my ...
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0answers
63 views

Freeing a binary tree data structure in C

I have this function that I hope to be a good alternative to the recursive (thus performance expensive) approach. ...
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2answers
74 views

Assign a unique number to duplicate items in a list

I made a program, but I not happy with the quantity of code. The end result is good, but I believe it can be made much easier, only I don't know how. The functionality: If equal items > 1 in list, ...
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2answers
265 views

Rotating an array by position n

Input is 1,2,3,4,5,6,7,8 If rotateOrder = 2 Output should be 7,8,1,2,3,4,5,6 If rotateOrder = 3 Output should be 6,7,8,1,2,3,4,5 Here is my program to do it: ...
4
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2answers
65 views

Make a map using a splay tree

In my data structures and algorithms class, we were introduced to the splay tree, a BST with the additional property that recently accessed elements are quick to access (because they stay at the top ...
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1answer
49 views

Retrieve annotation from a tree annotated with a Monoid

Working on this homework from 2013 for self-learning. For the following Algebraic Data Type: ...
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2answers
79 views

Parse a value to a given datatype

For our (internal) automated test project, I am writing a part where parameters can be passed to an SSIS Package before it gets executed. The tester delivers the parameter name, value and desired ...
6
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2answers
95 views

A reversed-string Trie data structure

This is a simple Trie data structure for strings, except it puts the strings into the structure backwards. The insert method simply iterates over chars from the string-to-be-inserted backwards, and ...
6
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2answers
191 views

Limited memory priority queue

I'm trying to implement a highly efficient limited memory priority queue. The interface is the same as a std::priority_queue. Can anyone suggest any performance ...
3
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1answer
119 views

Public interface for nearest neighbor data structures

I am making a small library of metric data structures. That is data structures, which associate points in the n-dimensional space with objects and allow the user to find objects which are closest to a ...
2
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1answer
298 views

Graph Implementation in Java 8

Here is my code which implements a simple directed graph in Java 8. Here are some of the things I am unsure about: I am fairly new to Java 8 concepts. Have I used the new API correctly (and not ...
6
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1answer
288 views

Generate Cartesian product of List in Java

My code, which generates Cartesian product of all lists given as arguments: ...
2
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1answer
56 views

Binary Search in C

The standard C library function bsearch wasn't giving me correct results, apparently. So I decided to implement a binary searching function in place of it. It ...
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2answers
224 views

Optimizing Dijkstra implementation using PriorityQueue in Java

I am trying to make Dijkstra implementation more efficient. Below is the code for class Node which implements Comparable so it ...