0448. Find All Numbers Disappeared in an Array.md

Array

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var findDisappearedNumbers = function(nums) {
    let res = new Array(nums.length + 1).fill(-1);
    let stack = [];

    for(let i = 0; i < nums.length; i++) {
        res[nums[i]] = nums[i];
    }

    for(let i = 1; i < res.length; i++) {
        if(res[i] === -1) {
            stack.push(i);
        }
    }
    return stack;
};