{ #category : #'as yet unclassified' }
CTOrderedSet >> allSubsets [
	"Generate all possible subsets of this self without self and an empty set.
	Example:
	{1, 2, 3} => {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}"
	
	"This implementation might not be very fast and has to be improved"
	^ (self combinations copyWithout: self asArray) collect: [ :eachArray |
		self species withAll: eachArray ]
]

{ #category : #'as yet unclassified' }
CTOrderedSet >> allSubsets [
	"Generate all possible subsets of the receiver, excluding the receiver itself and the empty set.
	Uses a bitmask approach for efficiency.
	Example: #(a b c) => #(a), #(b), #(c), #(a b), #(a c), #(b c)"
	
	| subsets size |
	size := self size.
	subsets := OrderedCollection new: (1 bitShift: size) - 2. "Reserve space for 2^n - 2 subsets"
	
	1 to: (1 bitShift: size) - 2 do: [ :mask |
		| subset |
		subset := self species new.
		1 to: size do: [ :index |
			(mask bitAt: index) = 1 ifTrue: [ subset addLast: (self at: index) ] ].
		subsets add: subset ].
	
	^ subsets asArray
]

{ #category : #'performance tests' }
CTOrderedSetTest >> testAllSubsetsPerformance [
	| set time |
	set := CTOrderedSet withAll: (1 to: 10) asArray. "Set of size 10"
	
	time := [ set allSubsets ] timeToRun.
	self assert: set allSubsets size equals: (1 bitShift: 10) - 2. "1022 subsets"
	self assert: time < 1 second description: 'Should complete within 1 second for size 10'.
]