Questions tagged [heuristics]
Questions about algorithmic strategies that quickly solve a problem well most of the time, but give no guarantees.
200
questions
1
vote
0answers
32 views
Which non convex optimization algorithms guarantee a global optima?
Most non-convex optimization algorithms I have come across so far rely basically on random restart to find a better solution. e.g. Genetic Algorithm, Simulated Annealing, Metropolis Hastings Monte ...
1
vote
0answers
15 views
Is there an heuristic for finding out the smallest height you can get when packing items in a tube?
It's sort of similar to bin packing, but instead of the minimum amount of bins,I was interested in just one infinite bin and finding out what's the smallest height you could get when you start packing ...
1
vote
2answers
49 views
Algorithm for optimal rule-based arrangements?
I am trying to plant a row in a garden. Certain plants are good for some plants and bad for others, and I am trying to find the best order of plants: most adjacent friends and no adjacent foes, as ...
1
vote
1answer
30 views
What solution to apply for finding the optimal parameters?
For a study, I have a system (black-box) that requires an input in the form of an array with 4 values (input_array) and depending on their values it produces an ...
0
votes
0answers
23 views
Search algorithm for vehicles moving through a square grid
I started to learn AI and I'm trying to solve the following problem like a search problem and I'm wondering which search algorithm would be the best in this case. Please give me at least some tips, I ...
0
votes
0answers
6 views
Ant Colony Optimization on Maximum Partitioning Graphs with Supply and Demand
I'm still new to the field of Computer Science and I'm having trouble understanding this paper An ant colony optimization algorithm for partitioning graphs with supply and demand. Can I ask for a ...
1
vote
0answers
36 views
What is an example of meta-heuristic algorithm for solving Mario NP-hard problem?
Applying entertainment with computations is my main motivation in studying Computer Science, however, I'm still a neophyte to this field. While searching across the net, I came across this paper ...
0
votes
0answers
15 views
Use of Tabu search Algorithm for solving optimization problem
I am trying to solve a maximization problem using the Tabu search algorithm but there is no relevant code available on the internet. Any kind of sample code is highly appreciable.
My function is F(...
1
vote
1answer
29 views
Proving 2 heuristics are admissible
We have $h_1(n)$ and $h_2(n)$ which are both admissible heuristics. We know that $h_1(n) < h_2(n)$ for every state $n$ in a search problem.
Now we are given two heuristics $h_3(n)=\frac{h_1(n)}{1+...
1
vote
0answers
29 views
Heuristic algorithm for the minimum weighted s-t cut with linear running time
To the best of my knowledge, the best algorithm for the minimum s-t cut in a weighted digraph is the Goldberg push-relabel algorithm with $O(n^{2}\sqrt{m})$ time complexity. I'm interested in solving ...
1
vote
1answer
44 views
Partition the indices of 2d array to minimize sum of sub-matrices
Given an $n\times n$ Matrix $M$, and the indices $[{1,2,3,4,...,n}]$ are divided into several intervals : $[1,x_1],[x_1,x_2],...[x_k,n]$, which further extract several squared sub-matrices along the $...
4
votes
1answer
141 views
Algorithm to create dense style crossword puzzles
I am working on creating a program to generate dense American style crossword puzzles of grid sizes between 15x15 - 30x30. The database of words I'm using ranges between 20,000 and 100,000 words of ...
0
votes
0answers
37 views
Least Constraining Value heuristic for graph coloring problem
The graph coloring problem involves assigning colors to vertices in a graph, such that no pair of adjacent vertices have the same color. I was given the problem to use least constraining value ...
1
vote
1answer
23 views
Do we understand when metaheuristics are optimal? (gradient descent & simulated annealing in particular)
Gradient descent sometimes works better than simulated annealing and vice versa.
Are there conditions under which we can prove that, given perhaps a restriction on the set of allowed algorithms, one ...
1
vote
0answers
25 views
Is this a valid heuristic for Dots and Boxes to reduce the branching factor of the search tree?
I am implementing an AI based on the MiniMax algorithm that plays the game Dots and Boxes. I would like to reduce the branching factor of the search tree, by introducing a heuristic rule that limits ...
0
votes
0answers
17 views
What does the gradient mean in evolutionary algorithm?
I have been reading about evolutionary algorithms and I often find the concept of gradient that is used as "to follow a gradient"...
0
votes
0answers
34 views
A heuristic for finding an edge cycle cover
I am looking to find a minimum list of cycles in a graph such that their union gives the list of all simple cycles in this graph.
In the example below, here are 4 simple undirected cycles: 1-2-3, 2-3-...
3
votes
0answers
26 views
Rearrange items in order reduce fragmentation and reduce wasted space
I have a segment with some offsets at irregular intervals
There are items of various length inside. Items cannot be placed randomly. Instead, their left side must match some offset.
Items are free ...
2
votes
0answers
39 views
Reaching local optimality in simulated annealing
I am currently reading about local search techniques. I understand that local search algorithms tend to get stuck in local optima and therefore usually do not find globally optimal solutions. Thus, ...
3
votes
1answer
139 views
Greedy Heuristics with an Altered Subset Sum/Partition Problem
Say we have a constant-time function that accepts some integer set. The function outputs True if we can split the integers into two subsets of an equal sum. If we can't partition the integers given, ...
0
votes
0answers
55 views
How do evaluation functions influence the optimal sequence of moves?
Assume you have a game tree and the features $(f_1, f_2, f_3,\ldots,f_n )$ that describe the state of the game at any node. Also assume that you are using depth-limited minimax and always expand up to ...
0
votes
0answers
194 views
What is the difference between nearest and cheapest insertion algorithms for a Traveling salesman problem?
I know that in the cheapest insertion algorithm we include the node which is not in the "base group" that has smaller cost given all possible combinations, and for the nearest we include the node with ...
1
vote
1answer
86 views
What is meant by a preemptive algorithm?
The definition on Google says 'serving or intended to pre-empt or forestall something, especially to prevent attack by disabling the enemy.'
So, how does this relate to an algorithm, especially the ...
0
votes
1answer
24 views
Comparison of constructive and local-search heuristics for TSP
In my high school class, we are currently looking at evaluating heuristic methods for intractable problems - especially TSP.
My question is what is the advantages or disadvantages of using a ...
2
votes
0answers
59 views
Matching of two weighted graphs allowing one-to-many mapping
I am looking for a heuristic for a graph matching problem as follows.
Given two graphs: $A$ (consisting of nodes $a_i$) and $B$ (consisting of nodes $b_i$). Typically the size of $B$ is larger than ...
2
votes
2answers
344 views
A* without heuristic more efficient than Dijkstra
I am using the module networkx to operate on graphs made from OpenStreetMap.
I wanted to compare the shortest path algorithm to ...
-1
votes
2answers
55 views
Can data be compressed through this hash function technique?
I'd like to know if this data compression scheme would work or not, and why:
Suppose we have a file. If we treat the bits that make up the file as the binary representation of a number n, we have n (...
4
votes
2answers
525 views
How do you prove a heuristic is admissible?
How does one prove that a suggested heuristic is admissible? Is this even possible?
For Example: Let's say I have the game Free Cell.
Rules: https://en.wikipedia.org/wiki/FreeCell
How can I ...
2
votes
1answer
75 views
Why is the usual simulated annealing algorithm using a Boltzmann probability?
I've coded a personal version for the simulated annealing problem, and I was wondering why, (other than by analogy to the physics), the probability is
$$ p = e^{-\dfrac{\Delta \text{length}}{T}}$$ (...
0
votes
0answers
47 views
What kind of standard deviation must be used in optimization algorithms?
I would like to ask about the standard deviation of objective function value.
There are two types of standard deviations:
Population standard deviation
Sample standard deviation
In metaheuristic ...
1
vote
0answers
172 views
Morphing Hypercubes, Token Sliding and Odd Permutations
A month ago, I asked the following question math.exchange (https://math.stackexchange.com/questions/3127874/morphing-hypercubes-and-odd-permutations), but for completeness, I will include the details ...
0
votes
0answers
288 views
How can an A* algorithm visit all nodes?
Is it possible to find the shortest path and visit all the nodes in a graph by A* algorithm? If yes, how?
0
votes
1answer
25 views
Term for an A*-like pathfinding strategy where only the heuristic goal distance matters
I am trying to find a proper term for the A*-like best-first pathfinding strategy where the node to expand next is the one with the least estimated distance from the goal, regardless of its distance ...
0
votes
1answer
77 views
Ant Colony optimisation for finding subsets with ~0 sum
I have a set A = [x1, x2...xn] where xi in R (real). I need to find all non intersecting subsets with subset sum ~0 (approximately equal to zero).
Since the set can have non zero real numbers, I have ...
2
votes
2answers
125 views
Does an optimal path imply the heuristic is admissible?
If we are given an A$^*$ path search with some heuristic $h$ that yields an optimal path, without knowing that the heuristic is admissible beforehand, would this imply that $h$ is admissible?
1
vote
1answer
159 views
Overall time complexity of Heuristical Algorithm for travelling salesman problem [TSP]
I am trying to figure out the time complexity of a heuristical algorithm used to solve the Travelling Salesman Problem in a more efficient way than by brute force, ($\theta(n!)$ or similar)
The ...
3
votes
1answer
32 views
Longest simple walk below a certain weight
Given a directed graph G and a starting vertex $v$ and a cutoff weight $w$, I want to find a simple walk with net weight < $w$ that visits as many nodes as possible. Currently, I have a recursive ...
1
vote
0answers
191 views
Travelling Salesman problem using Guided Local Search
I am doing Week_4 of https://www.coursera.org/learn/discrete-optimization/
stuck in solving TSP.
As there are a lot of methods to solve this problem, I am currently coding
Guided Local Search as ...
0
votes
1answer
33 views
Defining Local Search stopping criteria
When performing a local search, for example, a 2-node exchange in a metaheuristic (like GRASP), what is the usual stopping criteria for that procedure?
Some bibliography says that the local search ...
0
votes
0answers
324 views
How MAC-3(maintaining arc consistency-3) algorithm works?
I am studying CSP problems in artificial intelligence. I don't understand the MAC-3 algorithm especially line number 10. Could you tell me with step by step?
...
6
votes
1answer
142 views
Optimal partitioning of n-tuples
Motivation
Recently I was trying to optimize some API calls and reduced the problem to optimization of a cumulative number of identifiers across all the requests. I put some considerable effort into ...
1
vote
2answers
137 views
Choosing heuristic for A* algorithm where cost is less than absolute distance
Looking for information on choosing a heuristic for instances where the cost of traversing an edge can be less than one.
For example, say movement is allowed in the cardinal directions. Should all ...
0
votes
0answers
31 views
Relevance of the ZeroSum game to Heuristic search?
A question was posed to me as to the relevance of the ZeroSum game to Heuristic search algorithms.
I know that the zero sun game is a theory in which one persons gain is exactly balanced to another ...
1
vote
1answer
49 views
How to perform local search to find maximal induced subgraphs?
I'm looking for efficient ways to perform local search to find maximal induced subgraphs that satisfy certain properties : a tree, a forest or a bipartite subgraph for example.
What I mean by local ...
4
votes
1answer
212 views
Heuristics vs meta-heuristics vs hyper-heuristics?
The wikipedia page on meta-heuristics states that they are "heuristics designed to find, generate, or select a heuristic".
The wikipedia page on hyper-heuristics states that they are "heuristic ...
0
votes
0answers
47 views
can someone provide a good resource for understanding 2 opt heuristic?
I have looked into wikipedia and this MIT slide. A step by step iteration of the algorithm with a clear example would be appreciated.
0
votes
0answers
562 views
8 puzzle admissible heuristic where tiles are in correct position
For the 8 puzzle problem, it has been proved that if h(n) = number of tiles on wrong place. h(n) is an admissible heuristic as every tile which is in wrong place must be moved out at least once.
But ...
0
votes
0answers
44 views
How many states are examined in the most wins heuristic for tic-tac-toe (9-grid)?
I'm new to AI, and have a hard time to understanding how to count the total states are examined in the most wins heuristic for tic-tac-toe two plys deeper(9-grid)? Need help
-1
votes
1answer
173 views
How to prove if a heuristic function is admissible or not
Can somebody tell me how to solve this problem?
1
vote
1answer
573 views
Nearest Insertion Traveling Salesman Heuristic: is it faster to insert nearest nodes first?
I am trying to implement the nearest insertion TSP heuristic. However, I am wondering if it matters which node I insert into the subgraph first.
For example, should I start with one node; calculate ...
