LEETCODE 268 (JAVASCRIPT) | MISSING NUMBER

const MISSING = (nums, lower, upper) => {
let arr = [];
var set = new Set(nums);
for (let i = lower; i <= upper; i++) {
if (set.has(i)) {
arr.push(i);
}
}
return arr;
};

const MISSING = (nums, lower, upper) => {
let arr = [];
for (let i = lower; i <= upper; i++) {
if (nums.indexOf(i) == -1) {
arr[i] = i;
}
}
return arr;
};

Your videos are good just the volume is so soo low.

What about the case if there's a duplicate number in the array do we need to resort to the hashing or sorting method?

thanks for you work, seems like this solution not passing all the test for ex: [1,2,3,4,3], could you verify again?

awesome video, thanks andy!

Thank you. Excellent explanation!

Nice! Which website do you draw on?

The first way which you explained how to solve it does not work because if input is [0,1] it will not works for output 2.
I tried to solve it this way before i founded your video(:

Thank you for explaining this so clearly!