1899-merge-triplets-to-form-target-triplet.js

/**
 * @param {number[][]} triplets
 * @param {number[]} target
 * @return {boolean}
 */
var mergeTriplets = function (triplets, target) {
    var good = new Set();

    for (var t in triplets) {
        var triplet = triplets[t];
        if (
            triplet[0] > target[0] ||
            triplet[1] > target[1] ||
            triplet[2] > target[2]
        ) {
            continue;
        }

        for (var i = 0; i < triplet.length; i++) {
            if (triplet[i] === target[i]) {
                good.add(i);
            }
        }
    }

    return good.size === 3;
};

/**
 * https://leetcode.com/problems/merge-triplets-to-form-target-triplet/
 * Time O(N) | Space O(1)
 * @param {number[][]} triplets
 * @param {number[]} target
 * @return {boolean}
 */
var mergeTriplets = function (triplets, target, res = new Array(3).fill(0)) {
    for (const [a, b, c] of triplets) {
        /* Time O(N) */
        const [_a, _b, _c] = target;

        const isTargetGreater = a <= _a && b <= _b && c <= _c;
        if (!isTargetGreater) continue;

        const [__a, __b, __c] = res;
        res = [Math.max(__a, a), Math.max(__b, b), Math.max(__c, c)];
    }

    return res.every((val, i) => val === target[i]); /* Time O(N) */
};

/**
 * https://leetcode.com/problems/merge-triplets-to-form-target-triplet/
 * Time O(N) | Space O(1)
 * @param {number[][]} triplets
 * @param {number[]} target
 * @return {boolean}
 */
var mergeTriplets = function (
    triplets,
    target,
    res = new Array(3).fill(false),
) {
    for (const [a, b, c] of triplets) {
        /* Time O(N) */
        const [_a, _b, _c] = target;

        const isTargetGreater = a <= _a && b <= _b && c <= _c;
        if (!isTargetGreater) continue;

        res[0] |= a === _a;
        res[1] |= b === _b;
        res[2] |= c === _c;
    }

    return res[0] && res[1] && res[2];
};