{ "data": { "question": { "questionId": "2051", "questionFrontendId": "1923", "categoryTitle": "Algorithms", "boundTopicId": 851802, "title": "Longest Common Subpath", "titleSlug": "longest-common-subpath", "content": "

There is a country of n cities numbered from 0 to n - 1. In this country, there is a road connecting every pair of cities.

\n\n

There are m friends numbered from 0 to m - 1 who are traveling through the country. Each one of them will take a path consisting of some cities. Each path is represented by an integer array that contains the visited cities in order. The path may contain a city more than once, but the same city will not be listed consecutively.

\n\n

Given an integer n and a 2D integer array paths where paths[i] is an integer array representing the path of the ith friend, return the length of the longest common subpath that is shared by every friend's path, or 0 if there is no common subpath at all.

\n\n

A subpath of a path is a contiguous sequence of cities within that path.

\n\n

 

\n

Example 1:

\n\n
\nInput: n = 5, paths = [[0,1,2,3,4],\n                       [2,3,4],\n                       [4,0,1,2,3]]\nOutput: 2\nExplanation: The longest common subpath is [2,3].\n
\n\n

Example 2:

\n\n
\nInput: n = 3, paths = [[0],[1],[2]]\nOutput: 0\nExplanation: There is no common subpath shared by the three paths.\n
\n\n

Example 3:

\n\n
\nInput: n = 5, paths = [[0,1,2,3,4],\n                       [4,3,2,1,0]]\nOutput: 1\nExplanation: The possible longest common subpaths are [0], [1], [2], [3], and [4]. All have a length of 1.
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "最长公共子路径", "translatedContent": "

一个国家由 n 个编号为 0 到 n - 1 的城市组成。在这个国家里，每两个 城市之间都有一条道路连接。

\n\n

总共有 m 个编号为 0 到 m - 1 的朋友想在这个国家旅游。他们每一个人的路径都会包含一些城市。每条路径都由一个整数数组表示，每个整数数组表示一个朋友按顺序访问过的城市序列。同一个城市在一条路径中可能 重复 出现，但同一个城市在一条路径中不会连续出现。

\n\n

给你一个整数 n 和二维数组 paths ，其中 paths[i] 是一个整数数组，表示第 i 个朋友走过的路径，请你返回 每一个 朋友都走过的 最长公共子路径 的长度，如果不存在公共子路径，请你返回 0 。

\n\n

一个 子路径 指的是一条路径中连续的城市序列。

\n\n

 

\n\n

示例 1：

\n\n
\n输入：n = 5, paths = [[0,1,2,3,4],\n                     [2,3,4],\n                     [4,0,1,2,3]]\n输出：2\n解释：最长公共子路径为 [2,3] 。\n
\n\n

示例 2：

\n\n
\n输入：n = 3, paths = [[0],[1],[2]]\n输出：0\n解释：三条路径没有公共子路径。\n
\n\n

示例 3：

\n\n
\n输入：n = 5, paths = [[0,1,2,3,4],\n                     [4,3,2,1,0]]\n输出：1\n解释：最长公共子路径为 [0]，[1]，[2]，[3] 和 [4] 。它们长度都为 1 。
\n\n

 

\n\n

提示：

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