599. Minimum Index Sum of Two Lists

Description

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:

1. The length of both lists will be in the range of [1, 1000].
2. The length of strings in both lists will be in the range of [1, 30].
3. The index is starting from 0 to the list length minus 1.
4. No duplicates in both lists.

Solution

/**
 * Solved with hash table
 * @param {string[]} list1
 * @param {string[]} list2
 * @return {string[]}
 */
/**
 * @param {string[]} list1
 * @param {string[]} list2
 * @return {string[]}
 */
var findRestaurant = function(list1, list2) {
    "use strict";
    let table = {};
    for (let i = 0; i < list1.length; i++) {
        if (table[list1[i]] === undefined) {
            table[list1[i]] = i;
        }
    }
    let minSum = -1;
    let result = [];
    for (let i = 0; i < list2.length; i++) {
        if (table[list2[i]] !== undefined) {
            let curSum = i + table[list2[i]];
            if (minSum > curSum || minSum === -1) {
                minSum = curSum;
                result = [list2[i]];
            } else if (minSum === curSum) {
                result.push(list2[i]);
            }
        }
    }
    return result;
};