Combination of "r" strings from "n" strings

Question

I want anyone to answer a code for this question!!

Answer 1

Answer for the above question
#java
https://code.sololearn.com/cS4oDAW4BUpJ/?ref=app

Answer 2

I think he wants to print some substrings or subsequence from a word
//after an example it will be understood clearly

Answer 3

what u mean by combn. of r String from n String ?
//provide an example

Answer 4

(and a language)

Answer 5

i think what he want to say is that we have a string of n characters and we can take only r from that n characters and show various combinations of these r characters.

Answer 6

combine means selection different ways "r" names from" n" names

and I want a code from c or c++
from this piece of code we can achieve more things

Answer 7

Please provide 2 examples, it is not clear what to do.

Answer 8

Me neither, the maths are complex and the implementation is close to being trivial. I will learn about this when I need it.

Answer 9

This doesn't explain it well to me again.

Answer 10

@swim
your explanation is correct anyone can tell the combination
but
the main problem is to display those all different possible selection of products

Answer 11

That's also easy. Hint: use a set if you may use every product just once.

Answer 12

ex:- we have 10 products in which we have to select 5 products.
output: the number of different ways of selection of those 5 products