Subsets

Problem Link: https://leetcode.com/problems/subsets/

Choose or Don't choose Method

class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        
        ans=[]
        def recursion(nums,tempAns):
            if(len(nums)==0):
                ans.append(tempAns)
                return
            
            ch=nums[0]
            restofarray=nums[1:]
            temp=tempAns[:]
            temp.append(ch)
            recursion(restofarray,tempAns)
            recursion(restofarray,temp)
        
        recursion(nums,[])
        return ans

Faith Method:

class Solution:
    def subsets(self, nums: List[int]) -> List[List[int]]:
        
        if(len(nums)==1):
            return [[],[nums[0]]]
        
        tempAns=self.subsets(nums[1:])
        n=len(tempAns)
        ans=tempAns
        for i in range(n):
            temp=tempAns[i][:]
            # Take care of the above line [:]
            # Create another copy of that
            temp.insert(0,nums[0])
            ans.append(temp)
        
        return ans