thirdMaximumNumber.js

////////////////////////////////////////////////Third Maximum Number///////////////////////////////////////////
// Given an integer array nums, return the third distinct maximum number in this array. If the third maximum does not exist, return the maximum number.
// Example 1:
//
// Input: nums = [3,2,1]
// Output: 1
// Explanation:
// The first distinct maximum is 3.
// The second distinct maximum is 2.
// The third distinct maximum is 1.
// Example 2:
//
// Input: nums = [1,2]
// Output: 2
// Explanation:
// The first distinct maximum is 2.
// The second distinct maximum is 1.
// The third distinct maximum does not exist, so the maximum (2) is returned instead.
// Example 3:
//
// Input: nums = [2,2,3,1]
// Output: 1
// Explanation:
// The first distinct maximum is 3.
// The second distinct maximum is 2 (both 2's are counted together since they have the same value).
// The third distinct maximum is 1.
/**
 * @param {number[]} nums
 * @return {number}
 */
 const thirdMax = function(nums) {
    if(nums.length < 3) return Math.max(...nums);
    let u = new Set(nums);
    if(u.size < 3) return Math.max(...u);

    for(let i = 0; i < 2; i++){
        u.delete(Math.max(...u))
    }

    return Math.max(...u);
};

// console.log(thirdMax([3,2,1]));
// console.log(thirdMax([1,2]));
// console.log(thirdMax([2,2,3,1]));