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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python: area mapping using trigonometric circle

I have a car controlled by a raspberry pi, I would like to create maps to each place it visits. The solution I came up with is simple. Lets say you tell the car to go forward and then after 5 minutes ...
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1answer
111 views

Min weight feedback edge set with DFS?

Exercise from The Algorithm Design Manual 6-10. [4] Let G = (V,E) be an undirected graph. A set F ⊆ E of edges is called a feedback-edge set if every cycle of G has at least one edge in F. ...
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8answers
11k views

What methods are there to avoid a stack overflow in a recursive algorithm?

Question What are the possible ways to solve a stack overflow caused by an recursive algorithm? Example I'm trying to solve Project Euler problem 14 and decided to try it with a recursive ...
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0answers
238 views

Find sequences in a big data set of integers

I am working on algorithm for solving the integer factorization problem. My goal is to be able to recognize sequence in a big data set of integers. This is my premise, it based on experiments. The ...
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2answers
5k views

What is the best “bucket-fill” algorithm?

I'm pretty new to image processing, and I am currently working on a paint-like application that will feature a bucket-fill. However, I have no idea what the best algorithm for a bucket-fill is. I ...
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1answer
99 views

Algorithm to 'segment' a number into blocks of n?

I'm not sure how to word the title properly, but the problem goes something like this: I have 5 nodes, and node 0 is the "master". User inputs a number, e.g. 100 to the master. master "splits" the ...
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1answer
44 views

Boundary traversal in binary tree

How to perform boundary traversal in binary tree using only single traversal of the tree? I am doing it in this way (not a single traversal): void printBoundary (struct node* root) { if (root) ...
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1answer
98 views

What alghorithm can I use to find the biggest subarray within a 2d array with only n different numbers?

Let's say I have a 2d array 100x100 in size, each cell in that array has a number from 1 to 50 randomly. How do I find the biggest subarray in a rectangle size in that array that has only n different ...
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3answers
256 views

An algorithm for finding converse duplicates of ordered pairs

Given an array of ordered pairs of values, is there a well-known algorithm to find converse duplicates? [Converse meaning the same values, but in the opposite order.] That is, given ...
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1answer
91 views

dynamic programming with memoization

I’ve a problem with a programming exercise. I hope you can help me. In this exercise I need to find out what the maximum profit is of taking pictures from several items in a park. For taking pictures ...
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2answers
107 views

Estimating run time of algorithm

For instance if i have an algorithm that is O(n2) and it will run for 10 seconds for a problem size of 1000. Now if i were to double the problem size to 2000 i want to know the approximate run time in ...
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1answer
99 views

What algorithm-family or problem-space description fits? Industrial process feeding ingredients to process

Our process continuously feeds (normally <= 8) ingredients from a choice of hundreds, using 3 feeders only. So if ingredient count X is > 3, 3 through X are stirred together in a batch process and ...
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3answers
229 views

SQL - Algorithm for finding availability of a resource

I'm having trouble creating a mysql compatible algorithm for this. Background App with mysql, perl and JS. It's a booking system where each booking is comprised of a start, end and qty. Start and ...
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2answers
248 views

Traverse a matrix using a linear index to get an evenly distributed values sample

I'm looking for an algorithm idea on how to traverse a matrix using a linear index while avoiding row/column based traversals to get a more diverse distribution of values. To understand this better, ...
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1answer
26 views

Matrix distribution to process grid

I need to write a program, which will perform LU-decomposition, etc. The problem is that I don't know about the preferred way to distribute the loaded matrix from the root process to other processes. ...
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1answer
157 views

Solving a Sudoku variant with an unknown element

I recently stumbled upon a special Sudoku variant and am now struggling to effectively solve it programatically. Consider the following initial 6x6 grid: The rules The red question mark is ...
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15 views

Finding Contextual Nodes in a Knowledge Graph [migrated]

I'm currently participating in developing a knowledge graph that uses ConceptNet and a few others as its data sources. It uses the same architecture as ConceptNet namely it is stored as a hypergraph ...
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1answer
121 views

Algorithm to find minimal set

I have a set of sets S and I want to find a minimal set of elements M such that each set in S shares at least one element with M. S = set of sets ∀ f∈S ∃e · e∈f ∧ e∈M For example: S = {{1}, {1, 2, ...
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NullPointerException from tring to get seperate RGB components [migrated]

I am trying to get the seperate RGB components from each element in a 2D color array,but it keeps throwing a NullPointerException and I am not sure why. It might be something small that I missed, so ...
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10answers
6k views

Is it reasonable to assume that any physical quantity can be represented by a 64-bit integer without overflow or underflow?

The original binary search algorithm in the JDK used 32-bit integers and had an overflow bug if (low + high) > INT_MAX ...
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0answers
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PSO – how Dimensions are set up?

I am coding a Particle Swarm Optimization in C++. I have been for days trying to understand the theory of how dimensions work in each different problem. In the many examples I have seen, all of them ...
4
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4answers
584 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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1answer
60 views

timed events to modulation of real-time audio

I am new very to audio programming and am having trouble figuring out the right kind of algorithm for converting control events (e.g. like MIDI) to real-time sound genesis with a buffer. At the ...
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1answer
56 views

Connected components of undirected graph

Suppose I have an undirected graph G with vertices v1...vn and edges. Right now it is in adjacency list representation. For every time moment I have as input some subset of vertices that are "active" ...
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2answers
95 views

MJRTY - A Fast Majority Vote Algorithm isn't work [closed]

The MJRTY algorithm sets out to solve the problem of finding the majority element in a stream (an element comprising more than 50% of the stream). Moore proposed to solve this by using only 2 pieces ...
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3answers
244 views

Abstraction in algorithms

I asked some questions about algorithms, and some replied they are abstract concepts, however I don't know what abstraction means for algorithms or how it applies. For objects, I know if we remove ...
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54 views

A fast algorithm for a simple multi-objective minimization?

I have a set of n (arbitrary) integer numbers S which I want to partition into k subsets S_i each of size n/k (you can assume that k divides n). Let A be the arithmetic mean of elements of the set S. ...
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1answer
64 views

Should changes to FNV-1A's input exhibit the avalanche effect?

This is kind of related to Which hashing algorithm is best for uniqueness and speed?. In that question, the excellently written top answer notes, Randomnessification The other subjective ...
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1answer
151 views

Would adding more digits be a way to scale a order generation service? [closed]

I am working on interview questions from Amazon.com Software Development Engineer Intern Interview Questions. One of the interviewees was asked "give a scalable system design of Amazon.com's order ...
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9answers
6k views

Why is it impossible to produce truly random numbers?

I was trying to solve a hobby problem that required generating a million random numbers. But I quickly realized, it is becoming difficult to make them unique. I picked up Algorithm Design Manual to ...
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2answers
135 views

c++11 random: why different range of int and real?

In the c++11, we now have <random> to produce random number. About uniform distributions, we have following int_distribution and double_distribution: uniform_int_distribution-produces integer ...
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2answers
119 views

What is a formal definition for an algorithm step?

Consider the following code to find the K th minimum element of an array: FindKthMin(A[], k) { A = Sort(A); return A[k]; } Could it be an algorithm without specifying the sort details? ...
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2answers
170 views

What benefit is there to using recursive binary search over iterative binary search or vice versa?

In a recent assignment for my programming 2 class we tested the efficiency of searches by populating a java ArrayList with 13,040 strings. The sequential search was obviously slower than the binary ...
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30 views

Finding the largest bundle of flagged points

I am currently working to develop a program that takes in an array of 4 columns and around 200,000 rows. Each column represents x, y, z (coordinates), and a flag denoting whether or not this point is ...
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2answers
197 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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2answers
234 views

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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1answer
228 views

What is the most efficient / fastest way to keep a list in order?

I implemented Dijkstra's path finding algorithm in JavaScript and a big part of it involves storing the distances to nodes and fetching the smallest. The distances change often and the smallest is ...
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10answers
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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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2answers
49 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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3answers
166 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 ...
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1answer
4k views

faster algorithm for finding all subsets

This is the algorithm (pseudocode) I have right now for finding all subsets for a given set with length k: void allSubsets(set[]) { for (i = 0; i<k; i++) { for (j = i + 1; j<k; j++) ...
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2answers
128 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
74 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 ...
3
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3answers
266 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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1answer
79 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 ...
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3answers
262 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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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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2answers
218 views

Finding common prefixes for a set of strings

I am trying to find common prefixes for a sorted set of strings. i.e. if the following strings are given: AB123456 AB123457 ABCDEFGH ABCDEFGX1 ABCDEFGY XXXX then my function should return three ...
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1answer
52 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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41 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 ...