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## Problem

Given two arrays of strings list1 and list2, find the common strings with the least index sum.

A common string is a string that appeared in both list1 and list2.

A common string with the least index sum is a common string such that if it appeared at list1[i] and list2[j] then i + j should be the minimum value among all the other common strings.

Return all the common strings with the least index sum. Return the answer in any order.

Example 1:

Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["Piatti","The Grill at Torrey Pines","Hungry Hunter Steakhouse","Shogun"]
Output: ["Shogun"]
Explanation: The only common string is "Shogun".


Example 2:

Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["KFC","Shogun","Burger King"]
Output: ["Shogun"]
Explanation: The common string with the least index sum is "Shogun" with index sum = (0 + 1) = 1.


Example 3:

Input: list1 = ["happy","sad","good"], list2 = ["sad","happy","good"]
Explanation: There are three common strings:
"happy" with index sum = (0 + 1) = 1.
"sad" with index sum = (1 + 0) = 1.
"good" with index sum = (2 + 2) = 4.
The strings with the least index sum are "sad" and "happy".


Constraints:

• 1 <= list1.length, list2.length <= 1000
• 1 <= list1[i].length, list2[i].length <= 30
• list1[i] and list2[i] consist of spaces ‘ ‘ and English letters.
• All the strings of list1 are unique.
• All the strings of list2 are unique.

## Code

class Solution {
public String[] findRestaurant(String[] list1, String[] list2) {
Map<String, Integer> map = new HashMap<>();
for (int i = 0; i < list1.length; i++) {
map.put(list1[i], i);
}

int minSum = list1.length + list2.length;

for (int i = 0; i < list2.length; i++) {
String curr = list2[i];

if(map.containsKey(curr)) {
int indexSum = i + map.get(curr);
if(indexSum > minSum) continue;

if(indexSum < minSum) {
res = new ArrayList<>();
minSum = indexSum;
}