My head gets stucked finding an algorithm for my problem.
Assume I have N Numbers (lets say 4) and I want have ALL X-Partitions (X = N/2)
Example:
2-Partitions of {1,2,3,4} are: (1,2) (1,3) (1,4) (2,3) (2,4) (3,4) [Simply: all combinations]
I don t have a clue how to generate these combinations. If someone of you have an idea in Mind (I don t care what language. Pseudocode ist totally enough. I don t care if it s iterative or explicit).
Best regards, Bigbohne
Matlab has a function for this:
http://www.mathworks.com/help/techdoc/ref/nchoosek.html
>> x = [1,2,3,4]
x =
1 2 3 4
>> nchoosek(x, 2)
ans =
1 2
1 3
1 4
2 3
2 4
3 4
Loop constructs like maxwellb s are awfully slow in matlab...
Here s matlab code,
myNums = [2,3,6,5];
for i = 1:size(myNums,2)
combinationsSet{i} = nchoosek(myNums,i);
end
foreach i in SET
foreach j in SET
if i < j, SAY "I have a partition ($i,$j)"
NEXT j
NEXT i
this depends on an iterating feature for your set, and operates in N^2 time.
For Matlab, check out the functions provided for you, e.g. combnk
If I have an algorithm which is comprised of (let s say) three sub-algorithms, all with different O() characteristics, e.g.: algorithm A: O(n) algorithm B: O(log(n)) algorithm C: O(n log(n)) How do ...
I m using Electro in Lua for some 3D simulations, and I m running in to something of a mathematical/algorithmic/physics snag. I m trying to figure out how I would find the "spin" of a sphere of a ...
There s a (relatively) new sort on the block called Timsort. It s been used as Python s list.sort, and is now going to be the new Array.sort in Java 7. There s some documentation and a tiny Wikipedia ...
As a learning experience I recently tried implementing Quicksort with 3 way partitioning in C#. Apart from needing to add an extra range check on the left/right variables before the recursive call, ...
Given a 10 digit Telephone Number, we have to print all possible strings created from that. The mapping of the numbers is the one as exactly on a phone s keypad. i.e. for 1,0-> No Letter for 2->...
I have a directed graph and my problem is to enumerate all the minimal (cycles that cannot be constructed as the union of other cycles) directed cycles of this graph. This is different from what the ...
Given an array of integers arr = [5, 6, 1]. When we construct a BST with this input in the same order, we will have "5" as root, "6" as the right child and "1" as left child. Now if our input is ...
I was trying to speed up a certain routine in an application, and my profiler, AQTime, identified one method in particular as a bottleneck. The method has been with us for years, and is part of a "...