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.

public class Solution {
        public String[] findRestaurant(String[] list1, String[] list2) {
            HashMap<String,Integer> map = new HashMap();
            int v = list1.length + list2.length;
            List<String> st = new ArrayList();
            for(int i=0;i<list1.length;i++){
                map.put(list1[i],i);
            }
            for(int i=0;i<list2.length;i++){
                if(map.containsKey(list2[i])){
                    if(map.get(list2[i]) + i == v && st.size() >= 1){
                        st.add(list2[i]);
                    }
                    else if(map.get(list2[i]) + i < v){
                        v = map.get(list2[i]) +i;
                        st.clear();
                        st.add(list2[i]);

                    }

                }
            }
            return st.toArray(new String[0]);
        }
}