1436. 旅行终点站

https://leetcode-cn.com/problems/destination-city/

Java

/*
 * @Author: Goog Tech
 * @Date: 2020-08-29 11:53:34
 * @LastEditTime: 2020-08-29 11:53:52
 * @Description: https://leetcode-cn.com/problems/destination-city/
 * @FilePath: \leetcode-googtech\#1436. Destination City\Solution.java
 * @WebSite: https://algorithm.show/
 */

class Solution {
    public String destCity(List<List<String>> paths) {
        // 初始化用于存储起点名称的 HashSet 集合
        HashSet<String> startStops = new HashSet<>();
        // 循环遍历旅行线路集合,获取每个路径的起点名
        for(List<String> path : paths) {
            startStops.add(path.get(0));
        }
        // 再次遍历旅行线路集合,获取每个路径的终点名
        for(List<String> path : paths) {
            String dest = path.get(1);
            // 若起点名集合中不包含该终点名,则说明该点就是旅行终点站
            if(!startStops.contains(dest)) {
                return dest;
            }
        }
        // 无果
        return "";
    }
}

Python

'''
Author: Goog Tech
Date: 2020-08-29 11:53:45
LastEditTime: 2020-08-29 11:54:09
Description: https://leetcode-cn.com/problems/destination-city/
FilePath: \leetcode-googtech\#1436. Destination City\Solution.py
WebSite: https://algorithm.show/
'''

class Solution(object):
    def destCity(self, paths):
        """
        :type paths: List[List[str]]
        :rtype: str
        """
        # 初始化用于存储起点与终点名称的列表
        start, end = [], []
        # 遍历旅行线路集合,分别将起点与终点名存储到列表中
        for path in paths:
            start.append(path[0])
            end.append(path[1])
        # 遍历终点名称列表
        for des in end:
            # 逐个判断当前终点名是否被包含在起点名称列表中
            if des not in start:
                # 若不包含则说明该点就是旅行终点站
                return des