Longest Common Subpath - Practice Coding | SlaveCode
0
0123456789
0
0123456789
:
0
0123456789
0
0123456789
1923. Longest Common Subpath
Hard
50 Points
Array
Binary Search
Rolling Hash
Suffix Array
Hash Function
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.
Examples
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].
1923. Longest Common Subpath
Hard
50 Points
Array
Binary Search
Rolling Hash
Suffix Array
Hash Function
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.
Examples
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].