Package g1901_2000.s1923_longest_common_subpath

Class Solution

java.lang.Object
g1901_2000.s1923_longest_common_subpath.Solution
public class Solution extends java.lang.Object
1923 - Longest Common Subpath.

Hard

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.

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.

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.

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

Example 1:

Input: n = 5, paths = [[0,1,2,3,4], [2,3,4], [4,0,1,2,3]]

Output: 2

Explanation: The longest common subpath is [2,3].

Example 2:

Input: n = 3, paths = [[0],[1],[2]]

Output: 0

Explanation: There is no common subpath shared by the three paths.

Example 3:

Input: n = 5, paths = [[0,1,2,3,4], [4,3,2,1,0]]

Output: 1

Explanation: The possible longest common subpaths are [0], [1], [2], [3], and [4]. All have a length of 1.

Constraints:

  • 1 <= n <= 105
  • m == paths.length
  • 2 <= m <= 105
  • sum(paths[i].length) <= 105
  • 0 <= paths[i][j] < n
  • The same city is not listed multiple times consecutively in paths[i].

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    longestCommonSubpath(int n, int[][] paths)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • longestCommonSubpath

      public int longestCommonSubpath(int n, int[][] paths)