MinimumIndexSumOfTwoLists.js

// Source : https://leetcode.com/problems/minimum-index-sum-of-two-lists
// Author : Dean Shi
// Date   : 2017-08-16

/***************************************************************************************
 *
 * Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a
 * list of favorite restaurants represented by strings.
 *
 * You need to help them find out their common interest with the least list index sum.
 * If there is a choice tie between answers, output all of them with no order
 * requirement. You could assume there always exists an answer.
 *
 * Example 1:
 *
 * Input:
 * ["Shogun", "Tapioca Express", "Burger King", "KFC"]
 * ["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]
 * Output: ["Shogun"]
 * Explanation: The only restaurant they both like is "Shogun".
 *
 * Example 2:
 *
 * Input:
 * ["Shogun", "Tapioca Express", "Burger King", "KFC"]
 * ["KFC", "Shogun", "Burger King"]
 * Output: ["Shogun"]
 * Explanation: The restaurant they both like and have the least index sum is "Shogun"
 * with index sum 1 (0+1).
 *
 * Note:
 *
 * The length of both lists will be in the range of [1, 1000].
 * The length of strings in both lists will be in the range of [1, 30].
 * The index is starting from 0 to the list length minus 1.
 * No duplicates in both lists.
 *
 *
 ***************************************************************************************/

/**
 * @param {string[]} list1
 * @param {string[]} list2
 * @return {string[]}
 */
var findRestaurant = function(list1, list2) {
    const hash = {}, result = []
    let sum, index = Number.MAX_SAFE_INTEGER

    list1.forEach((l, i) => hash[l] = i)

    list2.forEach((l, i) => {
        sum = hash[l] + i
        if (hash[l] >= 0 && sum <= index) {
            if (sum < index) [index, result.length] = [sum, 0]
            result.push(l)
        }
    })
    return result
};