All Questions
Tagged with c++algorithms
71 questions
1vote
2answers
438views
Most efficient mapping of pixel to colors with colormaps
I'm working on a module that handles colormaps and I want to make the mapping of pixel to colors as efficient as possible. It is a performance critical section of our app. Our current solution works ...
- 493
0votes
3answers
849views
Mapping a range of values to a single value
So I have this problem where a specific ValuesA enum value is to be mapped to a respective ValuesB enum value, The trick is there can be multiple ValuesA mapping to a single ValuesB enum. So for the ...
- 109
1vote
2answers
484views
Efficient set method in run length encoded C++ map
I have been designing a C++ class that maps an integer to an integer using a vector. Because there is a lot of repetitive data (for example 11115555666222), I am using a compression scheme where I am ...
4votes
1answer
770views
Failure to understand logic behind dice roll permutation problem
I am having a lot of trouble understanding the logic behind the infamous "Find total ways to achieve given sum with n throws of dice having k faces" question. After extensively searching for ...
- 205
-3votes
1answer
586views
Is my algorithm for determining whether a ipv4 is public or private correct? [closed]
I have just created a function which checks whether a ipv4 is public or not. I have not heavily tested it yet since it is kind of practically impossible to do so (because I do not know where to start)....
0votes
1answer
543views
How to manually model a UML activity Diagram to JSON with Qt C++?
Suppose I have a kind of UML activity diagram with 1-n forks and joins. The assignment of the individual nodes relative to each other is defined by an XML relationship table via UUIDs where each ...
- 111
1vote
1answer
695views
Binary Search Tree with ID and Duplicate Values
I'm having trouble finding resources for this implementation I'm trying to figure out. I want to save nodes in a binary search tree (self balancing) containing an ID and value struct Score { int ...
7votes
2answers
1kviews
FIFO Min-Max-Heap for Rolling Median
I'm working on a system with hard real-time constraints in c++ and I need a very fast way to calculate the rolling/moving/streaming median of a set of numbers of size N=100 to 300. Normally this size ...
3votes
5answers
2kviews
Fastest way to find all numbers with digits
I have a huge set of over a million numbers of variable lengths. ['773', '2267', '8957251', '170597519', '373590109', '982451707', '999999937', ......] Now given a bunch of digits, say 3 and 7, I ...
- 141
3votes
4answers
119views
Store csv data as rows or columns in view of the needed processing?
Assume I have some data a csv-Files like ObjectName, PropertyA, PropertyB, PropertyC "Name1", 3, 1, 4 "Name2", 1, 5, 9 "Name3", 2, 6, 5 ... and a typical question I want to answer would be For ...
2votes
3answers
2kviews
Why did the C++ std library have a binary search tree well before a hashmap which is in many ways simpler
Looking at the two data structures and algorithms to handle them, a hashmap is not really any more complicated than a binary search tree and possibly less complicated. And the hashmap has the ...
- 1,813
3votes
1answer
1kviews
C++ generic graph search algorithm with generic data types
I'm trying to implement a generic graph search algorithm in C++, as part of assignment at university, and I encountered problems when trying to implement it, mostly struggling with templates. this is ...
- 33
-6votes
1answer
747views
What's the best algorithm to assign unique ID/serial numbers to a group of identical objects?
to make this question easier to visualize, let's call this the "chicken mesh problem". Suppose you have a rooster and a number (suppose it is 30) of baby chickens. Goal: Allow the rooster to ...
2votes
1answer
447views
Getting the number of bits set in a large integer
I have a large integer N < 10^2500. I need to get the number of bits set in its binary representation. The number is given in base 10 in a file. Here's how I'm doing it right now : I made a class ...
- 283
1vote
1answer
352views
How can I filter my coordinates system?
Following up with this, I have a bunch of coordinates and I draw them on a bitmap image as a coordinate system. Now, I would like to get rid of all the noise, and filter coordinates to give a "clearer"...
- 113
