containsDuplicate = (nums) => {
    const numsSet = new Set(nums);/* Time O(N) | Space O(N) */
    const isEqual = numsSet.size === nums.length;

    return !isEqual;
}
Hash Set
Time O(N) | Space O(N)
https://leetcode.com/problems/contains-duplicate/
@param {number[]} nums
@return {boolean}