help to solve this question

[dolly]

a set of n people(say a,b,c,d) need to assemble as two different teams in
two different rooms (say r1 and r2) to attend discuss two different
topics. participants are given options to pick the room of their interest,
print all the possible ways in which they can conduct the meetings.(while
printing the output, arrange the possiblities in such a way that no. of
people in r1 is in ascending order, and when the no. of people in r1 are
same, the groups are sorted based on their alphabetical order. note that a
set itself is printed as sorted character list. also assume 2<=n<=26)

sample input:
2

output:
- ab
a b
b a
ab -

[risby]

a set of n people(say a,b,c,d) need to assemble as two different teams in
two different rooms (say r1 and r2) to attend discuss two different
topics. participants are given options to pick the room of their interest,
print all the possible ways in which they can conduct the meetings.(while
printing the output, arrange the possiblities in such a way that no. of
people in r1 is in ascending order, and when the no. of people in r1 are
same, the groups are sorted based on their alphabetical order. note that a
set itself is printed as sorted character list. also assume 2<=n<=26)

sample input:
2

output:
- ab
a b
b a
ab -

I don't understand this at all. What does your sample input mean? Is it that there are just two people? If so then a will go to one room and b to another where they will talk to themselves. What do the space and the dash in your output represent?

[D_C]

Encode the problem using a binary string, and also use recursion.
Suppose n = 6. Then have a six digit binary string, modeled by a six entry boolean array. Then 000000 means all six people are in the first room, 111111 means all six are in the second room. For persons A, C, and D to be in the first room, while B, E, F are in the second, is 010011.

It's 51 lines of code. Of course, I could delete four sets of parenthesis and get it down to 43 lines of code.

Enter number of people: 4
-       abcd
d       abc
c       abd
cd      ab
b       acd
bd      ac
bc      ad
bcd     a
a       bcd
ad      bc
ac      bd
acd     b
ab      cd
abd     c
abc     d
abcd    -
Press any key to continue . . .

[D_C]

Actually, after thinking about it, recursion is not necessary. It's tail end, so it could be converted to a for loop. Then, you could encode the 2^N possibilities by counting from 0 to (2^N - 1).