Collections APIs provide developers with a set of classes and interfaces that makes it easier to handle collections of objects.

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4
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3answers
91 views

Generic sum method for a Collection<Number>

While answering this question, I wanted to use a generic sum of Collection function. Java doesn't have a native method, so I wrote one. There are a couple things ...
8
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2answers
188 views

Efficiently create and sort a Collection

The goal of my code is to sort data into two categories. It must use a local copy of the initial data from Collar (Top View).csv. My code creates a Collection of items called Collars using the initial ...
3
votes
2answers
132 views

Word Ladder Solution in Java using ArrayList

Word Ladder Given a start word and a goal word, convert the start word to the goal word by changing one letter at a time. Each step must also be a valid word. Is my code modular? I mean are ...
3
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0answers
30 views

C++11 lock free collection similar to std::forward_list - follow-up

Thread safe and lock free collections are very hard to write, so I'd appreciate any feedback, especially regarding bugs. The code below is a self contained cpp including some tests. This question is ...
3
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2answers
58 views

Wiring CollectionView and grouping it without slowing it down

In my previous question, I got heaps of good advice BUT no solution for the problem apposed. I applied the valuable learnings from the past on this.question and am also hitting it from a different ...
3
votes
3answers
86 views

Find intersection of two arrays without duplicates

A = [9, 1, 4, 2, 5] k unique integers B = [3, 1, 8, 7, 6, 5] n unique integers Intersection => [1, 5] Find an algorithm that uses \$O(1)\$ space (the space used by the return variable is not ...
3
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3answers
71 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 ...
2
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2answers
33 views

Remove list of files from another list of files by their name

In groovy I have a list of files A and also another list of files B. I want to remove all the files from A that have a filename that also occurs in the list of files B. I wrote the following code: ...
4
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1answer
61 views

C++11 lock free collection similar to std::forward_list [closed]

I'm new to explicit memory ordering, and any kind of thread safety is hard to implement right to begin with. Please let me know if you see any problems, or have suggestions for improvement. Written in ...
4
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2answers
46 views

Subsorting with multiple Comparators

I've seen a number of questions on Stack Overflow of the kind of "How do I sort on fields X AND Y?" The most common answers to those questions consists of "Write a custom Comparator." But what if you ...
10
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3answers
311 views

Collection with both Set and List interface

Here's something I wrote a while ago. I needed a collection that was ordered, but also guaranteed duplicates did not occur. So I made a class with both Set and List interfaces. It seems to work ...
6
votes
3answers
125 views

Extension method to enumerate a hierarchical object

I have a domain object that I have no control over which itself contains a collection of this same type. This is a classical hierarichal representation like in a tree node hierarchy. I would like to ...
4
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1answer
64 views

Container adaptors

How to improve the functionality, exception safeness and other aspects of the following container adaptors? Allows to write more generic code (not working for, say, ...
2
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1answer
94 views

ArrayList for Shop implementatin

Problem statement: Design a system for the following scenario: An item list contains item code, name, rate, and quantity for several items. Whenever a new item is added in the list ...
7
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1answer
44 views

Joining collections… because it's fun

I'm working on a LinqEnumerable class (reviewable here), and I'm no Big-O expert and I'm pretty bad with algorithms, so I wonder what the complexity is for what ...
-1
votes
1answer
176 views

ArrayList implementation in C [closed]

Although I know I can use calloc then realloc to make a dynamic array in C, and that I also need a variable to keep track of the ...
2
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2answers
292 views
2
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2answers
88 views

Performance enhancement for collection manipulation

I have below snippet of code which gets all the available menu items for a zone(top or left)and adds the widgets for which user has access to an ArrayList collection. For now the ...
7
votes
2answers
131 views

Array-like container for uints shorter than 8 bits (Rev 1)

This is a follow-up to Array-like container for uints shorter than 8 bits In short: The PackedBitfieldArray should be a kind of container for packed (unsigned) ...
11
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1answer
140 views

Array-like container for uints shorter than 8 bits

Follow-up: Array-like container for uints shorter than 8 bits (Rev 1) First of all: yes, I need this kind of array to generate data for a piece of hardware, and it must be stored and manipulated ...
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2answers
95 views

LinkedVector : a vector of elements with links to other elements

I wanted to have a vector with usual values and with some sort of indexing : an element can have links to other elements (via indices). Something like the following, where ...
10
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1answer
143 views

Container with sorted by multiple keys

From this question: Sorted vector (aka flat_set) for objects (pointers) with custom embedded key (functor used) This is an example of a multi-index container. Note: this is not a container as ...
5
votes
3answers
116 views

Finding the closest value in a collection in a game-server plugin implementation

I have an array of a instances of an enum type. A random double variable is initialized with a value between 0.... to 1, and should be used to get the closest ...
5
votes
1answer
224 views

Concurrent Linked Hash Set

Basically I want to create a concurrent LinkedHashSet which returns proper size too. I am mainly concerned about adding and removing iterations. Suggestions ...
5
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2answers
104 views

UniqueList Class in VBA

I often find myself abusing dictionary objects just for the exist method like this, ...
10
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3answers
306 views

Building a better Collection. Enumerable in VBA

VBA's 'Collection' is.... lacking, so, I've been working on a better Collection object that implements many of the features of C#'s Enumerable. This is very much inspired by this question and a follow ...
5
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2answers
144 views

Reducing the execution time of Online Community-Even Groups challenge

I have a coding problem for which I have attempted to solve with the below coding. However, my program is assessed as too slow in its execution and thus needs to be optimized to reduce the execution ...
10
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2answers
189 views

Sorting a collection

Related to, but not exactly a follow up of this question. After fixing some issues discovered in the last review, I added a little more functionality to the ...
8
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3answers
108 views

More imitation of Enumerable in VBA

I was inspired by Me How's question to see how far I could push an imitation of .Net's Enumerable Class. The new functions can obviously handle Collections, but can also handle any collection-type ...
2
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3answers
61 views

Code to evaluate a dotted quad IP address has clumsy use of inject/fold - can I match the pattern in Ruby?

I wrote this to consume valid IPv4 addresses in dotted-quad decimal form. ...
7
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2answers
181 views

Interface-based polymorphic collection

Here is a small C++11 utility collection to store any object that satisfies a given interface. Only the basic concepts are provided, I did not try to create a full collection: ...
8
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2answers
99 views

Splitting two lists into OnlyA, Both, and OnlyB

This is a part of my Minesweeper analyzer code that didn't fit into the last question. This code uses FieldGroup which ...
3
votes
1answer
85 views

Construct KD-Tree in Java

I want to construct KD-Tree from unsorted List of points in the plane (i.e. 2-KD-Tree). To do so I used the method from Wikipedia: http://en.wikipedia.org/wiki/Kd-tree#Construction This is my code: ...
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vote
1answer
106 views

Static map initialization [closed]

I have the following "working" static map: ...
8
votes
2answers
1k views

Efficient way of sorting a List based on multiple properties using Google Guava

I'm using Google Guava 17.0 library. I have a class named AroundBust containing only two properties id of type ...
4
votes
1answer
91 views

Finding the longest word from a list of words

I have a list of words (with repetitions), and I intend to find out the longest words amongst them, along with their length. My question is to know if my implementation is too verbose, is using too ...
9
votes
2answers
218 views

Twitter Streaming Client - Round#2

This is round #2. The initial code review is: Twitter Streaming API Client: Identifying the top trending hashtags for a specific term For a list of changes since the last review, please see this. ...
10
votes
3answers
2k views

Sorting numbers using Java Collections.sort()

Input is a file containing numbers in this format: 1.2 3 5.1 2 7 4 6 5 2 9.22 1 0.0 4 3 I am doing the sorting in the simplest way, using ...
2
votes
1answer
211 views

Generic util method to convert in single map from list of array of Object generally result of JPQL/ hibernate

I have designed a generic method to convert list of array of Objects to result into single map. This is working fine, but I want to check weather a key object is valid key (whether it is overriding ...
0
votes
1answer
102 views

Filter a collection

In my project, there are some methods which filter some items from a collection. I was told to use the C++ STL whenever I can. But when I use std::copy_if, I feel ...
7
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2answers
678 views

Deallocate all memory in a container of pointers

I want to erase all memory in a container. Currently I'm using this : ...
3
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0answers
110 views

Associative container that produces a unique, instance specific handle for each inserted object

It is not always possible to simplify program design by strictly managing the lifetimes of objects. If two objects have unpredictable lifetimes, but one of them needs to refer to the other, a simple ...
5
votes
4answers
382 views

Iterate over two collections of equal length

What's the best way to iterate over two collections of equal length? Currently I'm using this: ...
4
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2answers
97 views

Addition plus division taking up all my CPU - Kinect depth denoising

I have a method in my class that eats up something like 80% of my processor time while its running. In-fact one line within the method is responsible for the majority of this. The idea behind this ...
6
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3answers
124 views

Detecting available List operations

I'm writing some code which needs to take a generic java.util.List from another source and adapt to the available functions; eg. does it support ...
2
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3answers
115 views

Containers and lists

I want to create a container that has an AutoList object list. I wonder if my container is correct. ...
9
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1answer
344 views

Is my C++11 generic container a good design?

After refactors and refactors and the discovery of very common patterns on many of the classes of the software I wrote, I decided that it would be fine to have something like an arbitrary-keyed map, ...
4
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1answer
81 views

Does the class have unnecessary and violating Single responsibility principle method?

I encountered with the following code in the work. The MyItemCoordinator should receive MyItem objects, process them, add them ...
8
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2answers
126 views

Container for list of ranges

I made a C++ container of an ordered list of integers, that, in order to save space, I save as ranges: For example, the list \$ \{1,2,3,5,6,7,8,9,20\} \$ is saved in memory as \$ \{(1,3), (5,9), ...
10
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4answers
4k views

Implementation of stack using pointers

Please review my code and let me know how I can possibly improve it. ...