finding subset

[bunda]

Hi....
I have an array[4]={1,2,3,4}. I want to make a recursive program that will produce subsets from the array;
1
2
3
4
14
24
34
124
134
234
1234
is anybody could help me? thanks....

[JosAH]

Those subsets are all possible combinations C(n, k) for a set of n elements.
There are 2^n of those sets and you can easily find them if you count in
binary:

1 2 3 4
--------
0 0 0 0 = <empty set>
0 0 0 1 = { 4 }
0 0 1 0 = { 3 }
0 0 1 1 = { 3 4 }
0 1 0 0 = { 2 }
. . . .
1 1 1 0 = { 1 2 3 }
1 1 1 1 = { 1 2 3 4 }
 

kind regards,

Jos

[r035198x]

Those subsets are all possible combinations C(n, k) for a set of n elements.
There are 2^n of those sets and you can easily find them if you count in
binary:

1 2 3 4
--------
0 0 0 0 = <empty set>
0 0 0 1 = { 4 }
0 0 1 0 = { 3 }
0 0 1 1 = { 3 4 }
0 1 0 0 = { 2 }
. . . .
1 1 1 0 = { 1 2 3 }
1 1 1 1 = { 1 2 3 4 }
 

kind regards,

Jos

You wish everybody counted in binary too don't you?

[JosAH]

You wish everybody counted in binary too don't you?

:-) Well, it can come in handy now and then doesn't it?

kind regards,

Jos

[r035198x]

:-) Well, it can come in handy now and then doesn't it?

kind regards,

Jos

Some say it's the first sign of an addiction.


@OP You will need to put in a bit of work. The suggestion you got is as far we'll go until you put in some of your work.