0213-house-robber-ii.js

/**
 * Greedy - Max
 * Time O(N) | Space O(1)
 * https://leetcode.com/problems/house-robber-ii/
 * @param {number[]} nums
 * @return {number}
 */
var rob = (nums) => {
    const isBaseCase1 = nums.length === 0;
    if (isBaseCase1) return 0;

    const isBaseCase2 = nums.length === 1;
    if (isBaseCase2) return nums[0];

    const left = search(nums, 0, nums.length - 2); /* Time O(N) */
    const right = search(nums, 1, nums.length - 1); /* Time O(N) */

    return Math.max(left, right);
};

const search = (nums, start, end) => {
    let [left, mid] = [0, 0];

    for (let i = start; i <= end; i++) {
        /* Time O(N) */
        const temp = mid;
        const right = nums[i];
        const house = left + right;

        mid = Math.max(mid, house);
        left = temp;
    }

    return mid;
};