CodeEasy v0.1

Subsets

Medium Subject: Backtracking
Time Complexity
O(N * 2^N)
Space Complexity
O(N)

Problem Description

Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets.

Optimal Solution

Python 
def subsets(nums):
    res = []
    def backtrack(start, path):
        res.append(path[:])
        for i in range(start, len(nums)):
            path.append(nums[i])
            backtrack(i + 1, path)
            path.pop()
    backtrack(0, [])
    return res