Find All Numbers Disappeared in an Array

LeetCode題目: 448. Find All Numbers Disappeared in an Array

My solution:

/**
 * @param {number[]} nums
 * @return {number[]}
 */
let findDisappearedNumbers = nums => {
    let set = new Set(nums);
    let lostDigits = [];
    for(let i=0; i<nums.length; i++) {
        if(!set.has(i+1)) lostDigits.push(i+1);
    }
    return lostDigits;
};