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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Is recursion a declarative approach to solve the problems?

I have noticed many problems in algorithms textbook are solved by recursion (divide and conquer, backtracking,...) As I tried to enhance my skills in writing them, I have noticed, I just need to ...
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68 views

Approaches to get stats like average latency in last N seconds

I am receiving messages with latency information (LI, {date, latency}). For statistical reasons: (I am open to approx. approaches, stats monitor will be updated in 6-60 seconds) I want to monitor ...
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10answers
2k views

Do algorithms depend on computer architectures?

I read somewhere (forgot which book it is) that algorithms are independent of computer architectures. Some even say algorithms are themselves computation (machines?)? On the other hand, books on ...
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152 views

Why is the “period of a (pseudo)random number generator” important?

I've been trying to understand (pseudo)random number generator code from various sources and the concept of the period continues to elude me. To satisfy the minimum level of understanding, I've tried ...
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1answer
92 views

Algorithm for a fast search

I am looking for an algorithm (pseudocode, R code) for my problem here. This looks like a lot to read but is actually very very easy to read, and I am just trying to be verbose. I have a list (say ...
4
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2answers
441 views

Number of strings containing a specific substring

I've seen numerous questions (and answers) concerning the number of binary strings (e.g "10010" containing some binary substring (e.g "00"). I'd like to know if there is a way to generalize this: ...
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1answer
335 views

worst case comparisons for special case insertion sort [closed]

Consider an Insertion Sort with a Sentinel on n values, where every value occurs exactly twice in the input (so n must be even). So the best case input for comparisons is when the elements are ...
3
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3answers
311 views

“Read user input”: Could it be a step of an algorithm?

Based on this definition of algorithm from Wikipedia: In mathematics and computer science, an algorithm is a self-contained step-by-step set of operations to be performed. Algorithms exist that ...
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3answers
346 views

C# if statements

I am currently working on a C# checkers game for a university project in programming. But i have came to the point where i need to check whether a piece can be moved, or jump, but i feel like i'm ...
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3answers
190 views

number of strings, when each character must occur even times

I've been bashing my skull at this problem for some time now, and its really starting to frustrate me. The problem is: I have a set of characters, A, B, C, and D. I have to tell in how many ways a ...
2
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2answers
269 views

Dynamic Programming Problem - To find smallest integer number 'x' which contains only digits 1's and 0's such that x mod n = 0

To design an algorithm that will output the smallest integer number 'x' which contains only digits 1's and 0's such that x mod n = 0 and x > 0..... For example: 2 divides 10 3 divides 111 4 ...
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1answer
58 views

Accuracy proportional to size

I have lists of data I'm trying to organize where the list with the least variation/most precision/closest to the average and most amount of data is most highly rated. Some of the lists are like 2000 ...
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65 views

Dispatch Algorithm for logistics - Batch assignments

basically, I'm trying to implement an algorithm that dispatches drivers to deliver batches (a batch is a collection of orders). The algorithm takes all the batches and all the drivers available, then ...
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8answers
2k views

Relation between object orientation and algorithms

As I read some algorithms textbooks, they are full of clever procedures for some problems (sorting, shortest path) or some general methods (recursive algorithms, divide and conquer, dynamic ...
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4answers
140 views

What do polynomial algorithms entail?

From here, I know it is that an algorithm that... ...is said to be solvable in polynomial time if the number of steps required to complete the algorithm for a given input is O(n^k) for some ...
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1answer
116 views

Measure and locate areas of similar value in an image

I saw this picture online and wanted to see if I could create an algorithm to give ordinary images an effect like this: http://justinlivi.net/wp-content/uploads/2011/01/Living_In_Digital.jpg My idea ...
4
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2answers
152 views

Making a sequence strictly increasing by joining neighboring numbers using the smallest number of moves

I've got a following problem to solve: You are given a list of positive integers [x_1;x_2;...;x_n]. You are allowed to change 2 integers standing next to each other to one equal to their sum. (So ...
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4answers
274 views

How to convert the following node evaluation procedure to a non recursive solution?

I have the following recursive method. It evaluates a node (that represent a logical expression), using deep first search traversal : EvaluateNode(Node node) { bool result; switch(node.Type) ...
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2answers
409 views

Algorithm for merging multiple rows of data

I need an algorithm to merge multiple rows for data, where one column is the index column and if one or more rows have the same index value merge the column values into a single row, and lastly sort ...
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2answers
76 views

Resolve dependencies using before-after constraints

What i would like to do is the following. (Not sure if this question should go to StackOverflow, or here) Consider a datastructure like this: interface IAction { IAction[] afterActions() ...
2
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1answer
111 views

Closest Point to Moving Target

I have a target which is constantly moving, and only its current position is ever known. I also have about one hundred objects surrounding it, and for each of these only the current position is ...
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0answers
70 views

Finding all Triangular Hulls in a 2D Point Cloud

My question: Given a set of 2D points, enumerate all triples of points such that no other points is inside the triangle formed by those 3 points. I'm looking for something better than this: // The ...
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3answers
605 views

Situations when O(n^2) better than O(n*log(n)) [duplicate]

Is there any situation a sorting algorithm of time complexity O(n2) could be better than an O(n log(n)) sorting algorithm in any way?
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2answers
198 views

Sudoku hidden sets algorithm

I am writing a solver for the game sudoku. I am trying to implement the hidden set check in it and I can't figure out a way to do it well. I need to find out if there is a set of cells of size N in ...
2
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1answer
221 views

Genetic Algorithm's Tournament Selection limit to be selected

I started working again on a Genetic Algorithm and i'm trying a lot of operators and ways of selection. When I made the Tournament Selection , I noticed that it gets really easy to always get the top ...
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1answer
148 views

Algorithm to assign edges to smallest possible polygons?

I'm designing a procedural city generator, and the first step of the generation process is the creation of city streets. These streets extend out in a straight line to a point, then they can either ...
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4answers
419 views

Most efficient way to generate all descendents of all nodes in a tree

I'm looking for the most efficient algorithm to take a tree (stored as either a list of edges; OR as a list of mappings from parent node to a list of child nodes); and produce, for EVERY node, a list ...
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2answers
1k views

Efficient method for finding closest point to a line segment from a set of points including line segment's vertices

Let's say I have a list of points (in my case, point objects in a Python implementation). I then have a line segment connecting two of these points. I want to know if there's a way to efficiently ...
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2answers
398 views

Looking for a DP algorithm for a specific packing problem

I have the following problem to solve: Given a ferry with length d and a list of n cars conataining their length we must load the cars on the ferry in an order in which they appear in the list on 2 ...
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1answer
578 views

How to remove a middle element from queue?

I had a question, about how to remove an element from middle of the queue , without disturbing the order of other elements. E.g. Queue before operation:- <| a b c d e |< Queue after ...
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2answers
85 views

Greedy algorithms - minimising “parentheses rotatons” in order to get a valid expression

I'm preparing for an exam on which there will be problems solvable by DP, greedy algorithms. And one of the problem is - given a string containing parentheses in no particular order return a minimum ...
8
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2answers
578 views

How do personal assistants typically generate sentences?

This is sort of a follow up to this question about NLG research directions in the linguistics field. How do personal assistant tools such as Siri, Google Now, or Cortana perform Natural Language ...
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2answers
107 views

Method for determining if a line segment is an external edge of a Delauney triangulation?

I've created a Delauney triangulation of a set of points. Now I want to iterate over the triangulation and remove any line segments/edges on the exterior for which the following are true: The ...
3
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1answer
163 views

What algorithm can be used for a more complex version of the bin packing problem?

I'm currently developing a plugin for World of Warcraft in LUA to help optimize a recently introduced part of the game, namely Garrison missions. A Warcraft Garrison (basically a player fortress) has ...
2
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3answers
247 views

Test & remove, or always remove

I have a function to show or hide a certain UI control. In my example case below, the framework is jQuery I'm using for an event to show a tool tip that may fire a LOT (based on mouse movements) - but ...
4
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4answers
454 views

Why are return values from compare functions in many languages defined loosely?

Many languages define that compare functions should return ANY negative value, zero, or ANY positive value. Is there some reason that it shouldn't be clearly defined as -1 0 and 1? Does a wide range ...
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2answers
220 views

Big-O notation for other cases

I was just reading answers to a question Plain English explanation of Big O From that i came to know that Big-O notation is just an "upper bound" of the complexity of an algorithm? But can we apply ...
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2answers
671 views

What is the simplest and universal algorithm for parsing C++ code? [closed]

I need to do some project specific automatic checking of source codes written in C++ Limitations: Algorithm and its implementation should be simple, easily maintainable, extendable and ...
2
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1answer
155 views

How to randomly get or find a sub-tree (include root node) from a given tree that contains n leaf-nodes

I have a non-binary tree. I want to randomly find a "sub-trees" that are connected from root to leaf which must have at least n leaf-nodes (leaf-nodes of sub-tree must be leaf-nodes of given tree). ...
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2answers
445 views

Lower and Upper bound of an algorithm

I am learning about analysis of algorithms. I came across the term "upper bound" and "lower bound" in "worst-case" running time of an algorithm. Are they applicable to only the "worst case" or can ...
1
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2answers
492 views

Is it possible to protect client side algorithms 100%? [duplicate]

If you had a pretty novel idea that involved a new algorithm. Like lets say you were the first person to think of orbitz.com or kayak.com (travel sites) and you were able to and wanted to implement ...
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0answers
63 views

Syncing different nosql datasources efficiently

I have two dbs I am dealing with right now - Elasticsearch and Mongodb. Mongodb is legacy in the application in that I am not happy for its presence but it is there and in use, I am interested in ...
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2answers
128 views

Big O of 2 interesting Algorithmic functions [closed]

This is my homework(I have attempted it, and there are no references for questions like these) Determine whether or not these functions are polynomial run time and determine the constant c for ...
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1answer
490 views

Which weak algorithmic strategies I have that lead me to failing coding this simple algorithm? [closed]

I am a graduate student in computer science who graduated recently from a famous university. I applied to my first software engineering job and I failed the technical interview by failing to answer ...
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1answer
167 views

Algorithm to find the closest summation of elements in a list to a given number [duplicate]

Say I have a list {1,3,7,2,11,8,2} and I want to take x elements from the list and get the value 15.5. Is there an algorithm that would give me x elements in a list that, when added together, get ...
1
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1answer
91 views

find the minimum number of sets

Let's explain my question with example I have some integer sets for example S1 = {2,3} S2 = {2, 5} S3 = {4, 5} S4 = {4} S5 = {5} And I have sample set Ssample with 4 elements {2, 3, 4, 5}. So ...
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1answer
1k views

run time of nested while loop inside for loop

I'm here to clarify my understanding of the run times of these 2 algorithms: Algorithm1(n): For i = 1 to n j = 1 while i+j < n j = j+1 and Algorithm2(n): For i = 1 to n j = ...
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3answers
4k views

Efficient algorithm to count number of substrings divisible by 3

Given a string of decimal digits, I have to find the number of all substrings divisible by 3 in the range L to R [both inclusive], where L & R are index[1-based] of the specified string string ...
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1answer
118 views

What is the minimum cost graph inside a strongly connected component, which connects every vertex?

So for MST there are 2 possible definitions in an undirected graph. Keep in mind that in an undirected graph the MST algorithm always has n - 1 edges and no cycles. In an undirected graph, it doesn't ...
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3answers
269 views

Is there an algorithm to determine the amount of work needed to keep workers busy?

I wrote a multi-threaded program that randomly generates strings, and after generating, checks to see if the string contains a certain value. Namely, StringGenerator and StringChecker. What I'm trying ...