All combinations of properties in an array

Ok, I've been cheating on this thread for the last couple of days. Which is the tidiest (anything without a HUGE overhead) way to create an array of all possible combinations

var input = [
    {a: 1}, {a: 2, b: 3},
    {b: 4}, {b: 5}, {a: 6}


So, I want to generate the following:

var output = [
    {a: 1}, {b: 4}, {b: 5}, {a: 6},
    {a: 1, b: 4}, {a: 1, b: 5},
    {a: 6, b: 4}, {a: 6, b: 5},
    {a: 2, b: 3}


The thing is, in my particular case, I'm talking about 4 properties (and I really need to create a separate array for each set of different sets of properties, however, these are both things that I have to implement later), However, I'm only looking for some then psuedo generic code on how to approach this problem, not to someone writing this for me or something.

I feel like this should have been something I should have figured out, but I just don't get there. First, I create separate arrays for all combinations of properties (all a

's, all b

' s, all c

's, all ab

' s, all bc

, etc.). However, the point is that with three properties that you already have to add for each a

all b

, c

and bc

. Now writing this for a single property is easy enough, but writing a generic solution that does it for n-properties just eludes me entirely.


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1 answer

I'm not sure I really understand the requirements, but you can try a recursive solution along these lines (in non-javascript pseudocode):

def generate(i,C):
    # C is a dictionary representing the currently defined properties
    # We are allowed to add to our set of properties from the choices input[i],input[i+1],...

    # First choose a non-conflicting set of additional properties to add
    while i<len(input):
        if all of properties in input[i] are not in C:
             Add properties in input[i] to C
             Remove properties in input[i] from C





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