In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning.

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129 views

Algorithm for mapping users to a schedule based on time availability

I have a project where I must map employees to a schedule. The basic concept is: Company Opens between 08:30 and 17:00. Employee 1 can work from 08:30 to 12:00 then from 13:00 to 1700; Employee 2 ...
2
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1answer
122 views

What does 'upper bound' mean in context of BigO?

My computer science teacher says Big O has an upper bound but no lower bound. When I look at a graph of an algorithm mapped out using BigO though, there isn't an upper bound at all. The upper limit ...
0
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0answers
43 views

An algorithm to implement SQL's ORDER BY with TOP/LIMIT or OFFSET/FETCH

Is there a general algorithm to implement SQL's ORDER BY with OFFSET/LIMIT more efficiently than sorting all the records? The algorithm for a simple TOP x is easy enough. It takes one full pass ...
1
vote
1answer
183 views

Divide and Conquer Algorithm clarification needed

I have a homework assignment for a data structure/algorithm class. The task is to take an unsorted array of size n (example: [-8, 3, 2, -3, 3, 1, -3, -5]), and we have to use a divide and conquer ...
2
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1answer
290 views

Converting cron schedule to time intervals

I have, on the server, many jobs defined by users and some of those jobs are scheduled using cron expressions. I need to check (I can execute Groovy/Java on the server) if those jobs take longer than ...
0
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0answers
159 views

Tournament bracket customized algorithm

I'm in the making of a tournament for archery but i'm stuck because they want a specific match-matching for players. There is the usual 1-32,2-31,3-30 etc but the way they want the tree is a specific ...
3
votes
2answers
465 views

What makes for a bad case for quick sort?

I am learning about quicksort and want to illustrate different arrays that quicksort would have a hard time on. The quicksort I have in mind does not have an initial random shuffling, does 2 ...
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4answers
415 views

How to work around Java's lack of pointers to pointers when working with linked data structures? [closed]

I've learned from a textbook how to implement binary search trees recursively in Java, and am working on implementing them nonrecursively. I've found a simple and elegant way to implement an insert ...
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1answer
120 views

Is it possible to antialias existing lines, circles, text, etc. of a single color?

I want to manually antialias the output of GDI drawing functions on Windows. Each drawing function is rendered onto its own image and then blitted back (so alpha blending can work, as GDI doesn't do ...
0
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0answers
37 views

Is this synchronization required in service onCreate method?

Below is a sample code i captured from android doc Per service instance onCreate will be called only once. Ref: here and here The synchronization and singleton doesn't make any sense to me in this ...
0
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0answers
214 views

how to use Sql query to search text in CSV file and avoid iteration

I have one A File and many input files ,All files have CSV format . I want to match text of one column of all input files with one of the column of A file . I have stored all column value of File A in ...
0
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2answers
185 views

How are the tiles in WORDAMENT organized?

I'm trying to create a word game, just like WORDAMENT, in my spare time. In order to present a new round, I need to create a board with 16 letters organized in a 4*4 grid. Currently, I'm generating ...
0
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1answer
216 views

How is a floating point number represented in Java?

Which algorithm does java uses to convert floating point number (Ex:0.15625) into binary(0.00101)? Whether java uses normalized form or denormalized format? If I type float ab=0.15625 in Java source ...
2
votes
3answers
564 views

Find all possible subarrays of an Array

I am lost I just can't seem to get my head around backtracking/recursion approaches. I understand how simple recursion problems like factorials work I can even trace those by hand. But when it comes ...
3
votes
3answers
371 views

Need help identifying a league scheduling algorithm

I am trying to create a sports league scheduler. I am having trouble identifying an algorithm to help me efficiently fill in each slot. Sample data to build the schedule would be: 10 teams Each ...
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votes
1answer
112 views

Unevenly distributed random number generation [duplicate]

Let's say I have to generate random number from 1 to 100, however, the probability of each number is not 1/100, but a predefined probability. How to generate that number? I use Ruby/Python.
4
votes
2answers
184 views

algorithmic problem - Combining overlapping ranges

I'm looking for an idea to efficiently solve following problem: I have a set of pairs of ranges (range = a pair of numbers), each range is unique (but has same size) e.g. [ [(0,6),(34,40)], ...
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4answers
119 views

Efficient “Object with weights” structure

I need to find an "efficient" data structure / set of algorithms to do the following things: I have a list of objects. I need to assign them weights and later on increase or decrease these weights. ...
4
votes
2answers
101 views

To find the oldest/newest element in a heap

I want to find the oldest/newest element added into a heap of size k. At any given point of time if I have to find say the oldest element in the heap is there any approach with O(1) space and O(1) ...
0
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3answers
198 views

What does this function do?

Does this function means its calculating x=(x-1) + x^2? Function unknown(x) if ( x == 1 ) return 1 else return unknown(x‐1) + x*x
0
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0answers
83 views

What Algorithm can be use for task allocation based on location?

What algorithm can be use for task scheduling based on location? For example there are 100 students and 5 lecturers available. Each lecturer must get same amount of student using location allocation ...
0
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1answer
156 views

Count Sort Algorithm efficiency

As I am reading a Book about "Algorithm Analysis", I came across count_sort Algorithm. A question has been raised in my head. I read in many other papers, that "Quick Sort/ Merge Sort" are the best ...
0
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1answer
35 views

Tweaking a ranking algorithm from a few variables

I'm going to have a mySQL table with elements in it and would like to rank them in the same manner than Reddit but not quite. I'd like to know how to add or remove importance to a variable in my ...
2
votes
1answer
44 views

I have an unordered list of rectangles and their neighbors on four sides with no origin. How can I efficiently convert this into a grid?

I am writing a GtkGrid-like container for my GUI library for Go, and I'm trying to write the actual layout part of the code. Basically, I have an unordered list of controls. Each control is a ...
7
votes
3answers
280 views

Algorithms for making image mosaics - is there a quicker way than this?

I've been playing with making image mosaics. My script takes a large number of images, scales them down to thumbnail size and then uses them as tiles to approximate a target image. The approach is ...
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4answers
118 views

Is there a clever way to calculate a mode of an online series without storing the series?

My program's aim is to determine the correct time zone offset (GMT+k) as a series of numbers are fed to it. eg: -4 +11 1 -4 -4 So, here -4 (the mode of the series) is the correct value. But this ...
0
votes
1answer
58 views

Calculate which quantity packages to use based on quantity of bookings

In my app, many appointments can be booked for activities. Each activity has many price packages with a price and a quantity. On showing the cart, I need to work out what combination of packages ...
0
votes
1answer
149 views

How does stock brokers implement limit / trailing stop loss sell logic? [closed]

Let's take Fidelity for example, one can set to sell a stock with a trailing stop lost of 2% of last price, or even more simpler, one can set a limited sell order at any given price. And it must have ...
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2answers
167 views

How to measure algorithm accuracy?

I have a few optimization algorithms (for finding function minimum) and I'd like to check how good they are. Suppose I build test cases and compare the actual results to theoretical ones. What ...
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2answers
183 views

How to know whether to create a general system or to hack a solution

I'm new to coding , learning it since last year actually. One of my worst habits is the following: Often I'm trying to create a solution that is too big , too complex and doesn't achieve what needs ...
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votes
1answer
161 views

How to implement a genetic algorithm with distance, time, and cost [closed]

I want to make a solution to find the optimum route of school visit. For example, I want to visit 5 schools (A, B, C, D, E) in my city. Given the choice of five routes regarding what school I should ...
-1
votes
1answer
96 views

Finding “spare time” in a day from within a list of events

I have a list of events which is always sorted chronologically. The start time is always followed by the end time. Times are strings formatted as 'HHmmss'. // list of events var events = [ ...
7
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6answers
791 views

Algorithm to generate N random numbers between A and B which sum up to X

This problem seemed like something which should be solvable with but a few lines of code. Unfortunately, once I actually started to write the thing, I've realized it's not as simple as it sounds. ...
3
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2answers
169 views

Ranking players depending on decision making during a game

How would I go about a ranking system for players that play a game? Basically, looking at video games, players throughout the game make critical decisions that ultimately impact the end game result. ...
3
votes
2answers
159 views

How can I find the shortest path between two subgraphs of a larger graph?

I'm working with a weighted, undirected multigraph (loops not permitted; most node connections have multiplicity 1; a few node connections have multiplicity 2). I need to find the shortest path ...
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2answers
150 views

Looking for an algorithm to connect dots - shortest route

I have written a program to solve a special puzzle, but now I'm kind of stuck at the following problem: I have about 3200 points/nodes/dots. Each of these points is connected to a few other points ...
1
vote
1answer
136 views

Performing a Depth First Search iteratively using async/parallel processing?

Here is a method that does a DFS search and returns a list of all items given a top level item id. How could I modify this to take advantage of parallel processing? Currently, the call to get the sub ...
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2answers
71 views

Need to organize words based on their components, any other way aside from brute force?

I'm not sure if this process has a name. I have some words (about 9,000). They are in Japanese, but I'll try to explain this using English words. I want to categorize the words by the components (in ...
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votes
2answers
80 views

Can this word search algorithm be made faster? [closed]

Problem: Find a match of word S in text T Given: S and T are part of spoken and written English. Example: Match 'Math' in 'I love Mathematics' NOTE: Ignore CASES. My algorithm: STEP 1) Convert S, ...
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3answers
331 views

Finding the shortest path through a digraph that visits all nodes

I am trying to find the shortest possible path that visits every node through a graph (a node may be visited more than once, the solution may pick any node as the starting node.). The graph is ...
0
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0answers
87 views

Approach for packing 2D shapes while minimizing total enclosing area

Not sure on my tags for this question, but in short .... I need to solve a problem of packing industrial parts into crates while minimizing total containing area. These parts are motors, or pumps, ...
0
votes
2answers
116 views

How to avoid or minimise use of check/conditional statement in my scenario?

I have scenario, where I got stream and I need to check for some value. If I got any new value I have to store it in any of data structure. It seems very easy, I can place conditional statement ...
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2answers
47 views

Algorithm to match items be value into sets base on total

Given n sets of items. Each item has a value. The items in a set have similar values but vary by a small amount. The goal is to create new sets containing three items selected from the original sets ...
7
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2answers
1k views

single for-loop runtime explanation problem

I am analyzing some running times of different for-loops, and as I'm getting more knowledge, I'm curious to understand this problem which I have still yet to find out. I have this exercise called "How ...
2
votes
1answer
147 views

Asymptotic running time of for-loops

I have this question which I need answered: What is the asymptotic running time for the following piece of code? if (N < 1000) for (int i = 0; i < N; i++) for (int j = 0; j < N; ...
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votes
2answers
59 views

Know executables files launched/loaded by an executable file [closed]

I would like to know any executable files launched or loaded by an executable file (if possible without running it,if it is not possible i don't want any change in the system). For example i have ...
0
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2answers
389 views

Running time of simple for-loops

I'm reading algorithms and I understand most of it, one thing that I can still struggle with a lot is something as simple as running times on different for-loops. Everyone seems to have easy with ...
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1answer
103 views

City exploration algorithm

The purpose of the algorithm is to create n routes on a geographical map, where n is being given, whereas all routes take no longer than t time units by foot and end where they start, while trying to ...
0
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1answer
174 views

Dual pivot quicksort in face of expensive swaps

I was told this is better place to ask this TLDR Has anyone tested dual pivot quicksort performance with expensive-to-swap elements? It seems that in this case, it should massively underperform ...
4
votes
1answer
107 views

JS design pattern/algorithm for avoiding duplicate redraws in a fairly coupled system

Given: some sort of widget based web app lots of JS functionality high coupling (communication/callbacks between widgets) widgets draw themselves certain widgets need to do a complete and fairly ...