• Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

a question in building recursion..

 
alex lotel
Ranch Hand
Posts: 191
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
i got this question that i dond have any clue
what they want from me
it says:

build a method that takes two integer numbers
n>k>1
the method prints out all the subgroops
if the size of k
for example
subs(4,2)
prints
12,41,13,32,42,34

i cant find out was it the legality in these groops
because it meeses 22 31
??
 
Anand Hariharan
Rancher
Posts: 272
C++ Debian VI Editor
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Welcome to the forum.

It appears that they are looking for the number of ways you can select 'k' elements from 'n' elements (without considering arrangement). This is called COMBINATION (if arrangment is considered, it is called PERMUTATION).

In your example, '22' is disallowed because once '2' is picked from {1,2,3,4}, it cannot be selected again. Since we disregard arrangement, '31' is the same as '13', and '13' is a part of your "subgroup".

Am not sure if "subgroup" is a right terminology here, but I guess it depends upon the curriculum.

- Anand
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic