Tagged Questions

For questions about various search algorithms.

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How to implement an algorithm for specific kinds of search in a graph

Imagine i have a graph called G. G has some parts. In one part, every node describes a person. I have another part in G which contains interests as nodes. ( Imagine that person A likes music. So, ...
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Exhaustive Search

Suppose you have a vector of array with N elements, and each element can be an integer between 0 and M. For example, "1, 3, 0, 4, 0" where N = 5 and M = 4. I want to find this array by just doing an ...
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Weakly unimodal function using Golden Section Search

I was going through the Golden Section Search https://en.wikipedia.org/wiki/Golden_section_search and as I understand it should work for every unimodal function. Here, the definition of unimodal ...
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Improving Simulated Annealing based on Measure of Goodness

can anyone answer this question or direct me to a reference that can help? Simulated Annealing returns the current state when the end of the annealing schedule is reached and if the annealing ...
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Does this search method exist and what is it called?

I would like to search some function $f(x)$ "greedily" for a certain condition. Assume the condition $c = f(x_1)$ returned by this function is currently false and I can increase the input $x$ to the ...
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Binary search for the worst case.

I want to analyze binary search for the worst case, completely mathematically without any ellipses(...). I solved out the recurrence of the binary search. $$T(n+1)=T(n/2)+C$$ I've already searched ...
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2d search with high cost

I have a function f(x,y) that returns a fitness value, but calculating f(x,y) is very costly, and I expect a fair number of local maxima that are much lower than the global maximum. I do, however, ...
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How does Best First Search Calculate the Heuristic Values in the Graph

I understand that Best First Search uses a sorted open list based on Heuristic Values of the Nodes (priority queue) and a closed list.But how are these Heuristic values of the Nodes calculated? The ...
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Reducing TIC-TAC TOE State Space by using Symmetry in Artificial Intelligence

Im learning Heuristics in AI.I see that for brute force search there are 9! states.But the textbook says that first 3 levels are reduced by symmetry.How does that work?
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Optimally exploring a 2d grid

Given a 2D grid and an unknown starting location, what is the best way to search every node? The size of the grid would be known prior to starting but the method should scale easily.
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Exploiting geometric invariants via group theory

Let $T$ be the set of all plane triangles. The problem is to find $t \in T$ s.t.h. a predicate $P(t)$ holds. At present, I'm doing this by a form of randomized search procedure (effectively via a ...
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Need help understanding a simplification in a simultaneous search model.

The problem I am trying to solve is $\max_{k \in \mathbb{N}} \int_0^1 u d F(u)^k - ck$, where the associated utility is an iid random variable U following $F(\cdot)$ on [0,1]. $c > 0$ is the ...
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Find the three closest surrounding neighbors from a data

I have a data of coordinates $x$ and $y$ where we know the range of both variables, e.g. $(x,y)\in[0,1]^2$. So for a given any random point $\theta_0=(x_0~~y_0)^T$ in the range of $x$ and $y$ I would ...
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How to determine size and height balance of binary search tree?

I've been reading/ learning binary search trees and I've been stuck on the following question for a while now. I have the following tree, how do I determine the height and size balance of it? How do ...
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Searching Algorithm

A company database has 10,000 customers sorted by last name, 20% of whom are known to be good customers. When looking up a customer’s record in the database, the good customers account for 60%. Two ...
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A mathematical expression for “grid search”?

I've got a question whether there is a mathematical expression for a grid search? I have two parameters a and b in [0;1]. Depending on the values of a and b, I get a value for my function (the value ...
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n-dimensional searching alogrithm

If you want to store various points in a $n$ dimensional (here $n=2$) space. Is there a possibility to do that with a tree (as a binary-tree for $n=1$ is usually used) for efficient and fast finding ...
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The “find my car” problem: proper interpretation and solution?

This has been asked at least twice here, but both questions have accepted answers which are wrong. I don't really know any good way to draw attention to the question besides asking again and being a ...
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How to use binary search to find a function

I am reading somewhere that $$(\phi'(y))^{-1}=y^{-c_1}+y^{-c_2},$$ $c_1,c_2$ are some numbers, can be solved for $\phi$ using binary search. I am surprised because binary search binary search is used ...
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Infinite Search Tree Probibility

I have a question on Search Trees. I have a balanced, infinite, search tree. If you check a node at level $l$, the probability of finding a solution at that node is $p^l$. Questions The first ...
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Trivial case of $s \in T$

I was reading paper A Formal Basis for the Heuristics Determination of Minimum Cost Paths in section B "Some Definition About Graphs" there is footnote that say "We exclude the trivial case of \$s \in ...
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Median of medians algorithm

I am referring to the algorithm presented here used to find a good pivot: http://en.wikipedia.org/wiki/Selection_algorithm#Linear_general_selection_algorithm_-_Median_of_Medians_algorithm My ...