[leetcode] 78. Subsets

문제

Given an integer array nums of unique elements, return all possible subsets (the power set).

The solution set must not contain duplicate subsets. Return the solution in any order.

Constraints

1 <= nums.length <= 10
-10 <= nums[i] <= 10
All the numbers of nums are unique.

정답

/**
 * @param {number[]} nums
 * @return {number[][]}
 */
var subsets = function(nums) {
    
    let result = [[]];
    
    function backtracking(first, current) {
        for(let i = first; i<nums.length; i++) {
            current.push(nums[i]);
            result.push([...current]);
            backtracking(i+1, current);
            current.pop();
        }    
    }
    
    
    backtracking(0, [])
    return result;
};

핵심은 backtracking 할때 i+1 하여 전에 index와 중복되지 않게 하는 것!