LeetCode 15. 3Sum, in JavaScript

Problem

LeetCode 15. 3Sum — JavaScript.

Solution

https://leetcode.com/problems/3sum/solutions/2895033/javascript-sorted-typed-array-sliding-window/?orderBy=most_votes

const threeSum = numsArray => {
    "use strict";
    const nums = Int32Array.from(numsArray).sort();
    const results = [];
    const LAST  = nums.length - 1;

    let i = 0;
    do {
        const n = nums[i];
        if (n === nums[i-1]) continue;
        let l = i + 1;
        let r = LAST;
        const isPossible = (n + nums[l] + nums[l+1] <= 0);
        if (!isPossible) break;
        do {
            const ln = nums[l];
            const rn = nums[r];
            const testSum = n + ln + rn;

            if (testSum === 0) {
                results.push([n, ln, rn]);
                // Increment l; decrement r.
                // To avoid duplicate triplets,
                // repeat until unique values appear.
                //  E.g. [-10, 2, 3, 3, 7, 8]
                // [[-10, 2, 8] [-10, 3, 7]] NOT 2nd [-10, 3, 7]
                while (ln === nums[++l]);
                while (rn === nums[--r]);
            } else if (testSum < 0) {
                l++;
            } else {
                r--;
            }
        } while (l < r);
    } while (++i < LAST)
    return results;
};Code language: JavaScript (javascript)

Interactive Web Demo in JavaScript

https://mybanned.com//wp-content/uploads/2023/01/3sum.html

Video