Re: mathematical combination

On Nov 21, 10:44 am, keny...@xxxxxxxxx wrote:
Hi!
I'm new to C++ but I have a challenge to write a program to find the
different mathematical combinations of p and t objects respectively
from a total of n objects i.e. nCp and nCt.The program should display
the various combinations.
A further aspect is to find the intersection between nCp and nCt
i.e.each set of nCp that contains each of the possible combinations of
nCt without considering the order of appearance.
Let me try to be clearer,pls:
say n=7,p=5 and t=3
1. I want a program to find 7C5 and 7C3
2. I want a display of the possible combinations in each case i.e
for 7C5; (12345),(12346),(12347),(13456)etc and
for 7C3; (123),(124),(125),(126)etc
3. Finally, the intersection e.g.
(123) intersects (12345),(12346),...
(124) intersects (12345),(12346)...
(125) intersects (12345)
and so on.
Your help will be appreciated.Thanks.

Look up "Pascal's Triangle" for a table lookup approach to the nCr
problem.

Do you know what your domain is? In other words can you have 200 C
5? How about 1000 C 7?

If the domain is large, it will quicky become infeasible to list the
combinations. For instance, this is the Pascal's Triangle table for
n=100:

static const long double d100[] =
{
1.
,100.
,4950.
,161700.
,3921225.
,75287520.
,1192052400.
,16007560800.
,186087894300.
,1902231808400.
,17310309456440.
,141629804643600.
,1050421051106700.
,7110542499799200.
,44186942677323600.
,253338471349988640.
,1345860629046814650.
,6650134872937201800.
,30664510802988208300.
,132341572939212267400.
,535983370403809682970.
,2041841411062132125600.
,7332066885177656269200.
,24865270306254660391200.
,79776075565900368755100.
,242519269720337121015504.
,699574816500972464467800.
,1917353200780443050763600.
,4998813702034726525205100.
,12410847811948286545336800.
,29372339821610944823963760.
,66324638306863423796047200.
,143012501349174257560226775.
,294692427022540894366527900.
,580717429720889409486981450.
,1095067153187962886461165020.
,1977204582144932989443770175.
,3420029547493938143902737600.
,5670048986634686922786117600.
,9013924030034630492634340800.
,13746234145802811501267369720.
,20116440213369968050635175200.
,28258808871162574166368460400.
,38116532895986727945334202400.
,49378235797073715747364762200.
,61448471214136179596720592960.
,73470998190814997343905056800.
,84413487283064039501507937600.
,93206558875049876949581681100.
,98913082887808032681188722800.
,100891344545564193334812497256.
};


When you display your results, is order important?
.

Relevant Pages

  • mathematical combination
    ... A further aspect is to find the intersection between nCp and nCt ... I want a display of the possible combinations in each case i.e ... intersects,,... ...
    (comp.programming)
  • dots instead of grid lines
    ... just display a dot where each vert/horiz line ...
    (microsoft.public.excel.worksheet.functions)
  • IMO 2004
    ... ABC is acute angle triangle with ABAC. ... intersects the lines AB and AC respectively at M and N. O is the ... Define a "hook" to be a figure made up of six unit squares as shown ...
    (sci.math)
  • Re: 2D circle-triangle intersection test
    ... > could someone point me in the direction of a fast circle-triangle ... check if the circle's center is inside the triangle. ... the center is inside the triangle, be safe that the center intersects the ... then the circle does not intersect the sphere. ...
    (comp.graphics.algorithms)
  • Re: Joining points to form 3D convex polygon
    ... out where each edge of the triangle intersects the polyhedron and also ... where each edge of the polyhedron intersects the triangle. ... shared plane). ...
    (comp.graphics.algorithms)