599. Minimum Index Sum of Two Lists

- 日理万妓 2022-05-29 03:22 116阅读 0赞

原题链接：[https://leetcode.com/problems/minimum-index-sum-of-two-lists/description/][https_leetcode.com_problems_minimum-index-sum-of-two-lists_description]

import java.util.*;
    
    /** * Created by Joe on 2018/3/15. * 599. Minimum Index Sum of Two Lists * https://leetcode.com/problems/minimum-index-sum-of-two-lists/description/ */
    public class P599 { 
        public String[] findRestaurant(String[] list1, String[] list2) {
            Map<String, Integer> map = new HashMap<>();
    
            //加入值和索引
            for (int i = 0; i < list1.length; i++) {
                map.put(list1[i], i);
            }
    
            //查找最小值
            int least = Integer.MAX_VALUE;
            List<String> list = new ArrayList<>();
            for (int i = 0; i < list2.length; i++) {
                if (map.containsKey(list2[i])) {
                    int index = map.get(list2[i]);
                    if (i + index < least) {
                        least = i + index;
                        //看到评论区提到，因为GC问题，使用
                        //list = new new ArrayList<>();会更好
                        list.clear();
                        list.add(list2[i]);
                    } else if (i + index == least) {
                        list.add(list2[i]);
                    }
                }
            }
    
            return list.size() == 0? null : list.toArray(new String[0]);
        }
    }

**注：**  
这个代码写的时候没有一次过，主要的问题就是审题不当，以为`least index sum`只会出现一次。实际上会出现多次，所以使用`list`是很好的方式

[https_leetcode.com_problems_minimum-index-sum-of-two-lists_description]: https://leetcode.com/problems/minimum-index-sum-of-two-lists/description/