Increasing Triplet Subsequence

LeetCode題目: 334. Increasing Triplet Subsequence

My solution:

/**
 * @param {number[]} nums
 * @return {boolean}
 */
let increasingTriplet = nums => {
    let smallest = Number.MAX_VALUE, smaller = Number.MAX_VALUE;
    for(let num of nums) {
        if(num <= smallest) smallest = num;
        else if(num <= smaller) smaller = num; 
        else return true;
    }
    return false;
}