# Questions tagged [arrays]

A sequential random-access data structure whose size can typically not be changed after creation.

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### What is the average-case running time of Fun-sort?

I read this paper: http://www.sciencedirect.com/science/article/pii/S0166218X04001131?np=y (you can check the PDF online for free), and I translated section 4's Fun-sort algorithm (correct me if I'm ...
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### Sort 2D arrays so that cost of reaching new position as described at each iteration is minimized

Problem is as following: We are 8 trumpet players in an orchestra. There are for example 4 parts so there are always two players on the same part. Now, there are not always the same two players ...
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### Merge two sorted arrays without using additional memory

We have two sorted arrays of integers. Without using additional memory we need to merge these two arrays such that the smallest numbers are in the 1st array and the remaining numbers are in the ...
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### Sort array of duplicate integers in place

Given an array of integers within [1, n] where n = size of array, some elements may appear more than once. Could we sort it with just 1 extra space and in O(n) time?
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### Find the median of two sorted arrays of different size in O(min(log(n),log(m)) complexity

Given two sorted arrays of length m,n, how do I find the median of the union of these two arrays in O(min(log(n),log(m)) time? I've been trying to come up with an algorithm (and a proof) for several ...
687 views

### Algorithm for solving rectangle puzzle

Early note: This is not homework. I simply regularly create ideas in an attempt to teach myself a language. For what it's worth I'll be using Javascript for this. That said, I haven't been able to ...
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### Improve algorithmic complexity

We have an array of N size. We have to perform Q queries on it, in which each Query contains and Index I for which we do: ...
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### How to find the top k pairwise product of in an array of integers?

Input: An array $a$ of integers $[a_{1}, \cdots, a_{n}]$, and a positive integer $k$. Output: The the top-k products of pairs in $a$. Example: $a = [7,6,5,4,3,2,1],k=3$ , output $(42,35,30)$, with ...
469 views

### Understanding the Polyhedral Model

I am wondering at a high level the mathematics of the Polyhedral Model. The polyhedral model (also called the polytope method) is a mathematical framework for programs that perform large numbers of ...
785 views

### Sub-dividing a 2d array into regions

Suppose I have a array of real numbers with $n$ rows and $m$ columns. I want to consider possible ways of dividing that array into rectangular regions of three different possible types: a constant ...
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### Array counter with mimimum find

I need to implement data strucure such as array, but with the following interface: GetMin() - Returns the minimum from the array IncRight(index) - Increases all values from specified index to the end ...
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### Why can't fractional cascading be used on two unrelated arrays?

According to both Wikipedia and my professor (see question 5.1), fractional cascading has to be done on arrays with related data. The specific question: A fellow student wants to compactly store ...
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### Find the nearest sum to a given number of two elements in sorted matrix

Given a sorted $n\times n$ matrix $A$ of real values. That is $a_{ki}<a_{kj}$ and $a_{it}<a_{jt}$, when $i<j$. Propose and algorithm, finding two elements of this matrix with the sum nearest ...
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### Longest Increasing Subsequence

I got no responses on stackoverflow, so I'm asking here: How useful is the LIS (Longest Increasing Subsequence) problem in tackling other CS problems? There are a few algorithms, using patience ...
118 views

### Algorithm to find out the number of times a number occurs consecutively in an array in a range specified

I have an array say 8 3 5 4 4 4 4 4 3 2 7 11 12 7 7 7 7 1 2 total =17 elements now you are given a range say [2,11] both included ,now you have o find out the ...