All Questions
Tagged with algorithms performance
72 questions
1
vote
1
answer
195
views
How do I narrow down a search space if symmetries are equivalent?
I have an algorithm that runs a search through every combination of a 5x5 grid where each cell can have 3 values, looking to see which combinations meet certain conditions. This gives 3^25 naive ...
- 465
0
votes
3
answers
754
views
Why isn't a counter used to avoid nested for loops for index based operations?
Let's assume we have a method that we want to run as fast as possible and it needs to loop on a 2D array, naturally we would do a nested for loop as such:
int[][] arr = new int[3][3];
for(int ...
- 51
2
votes
1
answer
2k
views
Multiple if condition optimization
Often I find conditional statements such as:
if (life_max < max):
if (expand):
do life_max = max
else:
if (life_max > max) and not (expand):
do life_max = max;
Although readable, ...
- 1,355
5
votes
4
answers
641
views
Processing a 2D matrix - need to speed up my O(n^4) algorithm
I have an n x n matrix which I need to convert into a list sorted by value. Starting with the maximum value cell at (row x1, col y1), I must immediately exclude all cells where (x >= x1, y <= y1)...
- 187
21
votes
6
answers
5k
views
Using a different algorithm depending on the size of the input
I recently finished a course on advanced algorithms, and another on complexity & computability theory, and in the past few days my mind has been somewhat preoccupied by this question.
Why don't we ...
- 345
-3
votes
2
answers
1k
views
Which hash algorithm is best for speed and identical hashes. (a lot of collisions)
I'm searching an existing hash function or trying to make a hash function that has a lot of collisions.
Regularly a hash is used for it's ability to create unique hashes for hash tables or security ...
5
votes
5
answers
1k
views
How can billion integer ids be stored and specific ones checked for existence most efficiently? (persistent solution, not just in-memory)
Let me preface this by saying that I am familiar with RDBMS. I have a solution using mysql/mariadb but I am not happy with the efficiency of the solution so I'm looking for alternatives.
I'm trying ...
- 69
0
votes
1
answer
108
views
Booking problem
The initial task was to find very quickly, free time for resources, let say - hotel rooms, services availability.
I came with following model:
Let say we have 24h in 1 day, and 365(366) days in a ...
- 101
0
votes
1
answer
294
views
Need to test for equality on vector clocks
I've heard about vector clocks and how to test if a message was sent before another message.
E.g. Message A was sent before message B if every element of the vector of message A is smaller or equal ...
- 111
2
votes
1
answer
117
views
Quantity allocation algorithm performance
I have a scenario for which I'll take an analogous example to help understand better.
There are N buckets of known varying capacities.
We have M balls that we need to put in these buckets to fill ...
- 129
0
votes
1
answer
169
views
How large-scale production web crawlers improve performance when it comes to running into already visited links
I have built a very basic webcrawler running off my laptop so it has limited memory and limited hard drive space. The way I have it now is I'm using MongoDB to store the links I find on pages. I make ...
- 131
1
vote
1
answer
87
views
Calculation On Large File Data
I have a task where I need to read a big data file and process the data in it. Every row in the file looks like this:
CustomerId ItemId Amount Price
I need to calculate the total cost for the ...
- 171
-2
votes
1
answer
2k
views
Is algorithm performance dependent on the programming language used? [closed]
I have studied complexity of algorithms that how long an algorithm will take to execute completely, then why it is said that certain programming languages are faster than others such as C++ is faster ...
- 27
0
votes
1
answer
41
views
Assembling random indexed packages into an ordered sequence(s)?
I am pretty confident that this is well-known and solved problem.
Suppose there are n uniquely indexed "packages" randomly getting into single entry point like .AcceptPackage(Package package). ...
- 345
1
vote
1
answer
167
views
What tools exist to determine the speed up a GPU will have on an algorithm?
Basically, I am wondering what sort of speed I will get by parallelizing a algorithm to work with GPUs. I am wondering if someone has implemented queueing theory/Amdahl's law with a UI or if everyone ...
- 1,132