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Deven
31 lines
1.1 KiB
Python
31 lines
1.1 KiB
Python
class Solution:
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def subsets(self, nums: List[int]) -> List[List[int]]:
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# All subsets can be mapped to a binary number where
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# - the number is the same length as the list
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# - a 1 represents the number being in the list, 0 otherwise
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# Example: nums = [1,2,3]
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# subsetBinary = 0 = 0b000 -> []
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# = 3 = 0b011 -> [2, 3]
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# (2 ** 3) - 1 = 7 = 0b111 -> [1, 2, 3]
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import math
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powerSet = []
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for subsetBinary in range(2 ** len(nums)):
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subset = [nums[i] for i in range(len(nums)) if (((2 ** len(nums) - 1) - (2 ** i)) | subsetBinary == (2 ** len(nums) - 1))]
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"""
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# Iterates exactly n times (where n is the number of 1s in the binary string)
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while subsetBinary > 0:
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indexOfFirst1 = -(math.floor(math.log2(subsetBinary)) + 1)
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subset.append(nums[indexOfFirst1])
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subsetBinary -= 2 ** (-indexOfFirst1 - 1)
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"""
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powerSet.append(subset)
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return powerSet |