jm-leetcode

/**
 * @param {number[]} nums
 * @return {boolean}
 */
var containsDuplicate = function(nums) {
    const map = {};
    for (let num of nums) {
        if (num in map) return true;
        map[num] = num;
    }
    return false;
};
var containsDuplicateSet = function(nums) {
    return new Set(nums).size !== nums.length;
};
containsDuplicate([1,2,3,4,5,1]);