Package g2201_2300.s2246_longest_path_with_different_adjacent_characters

Class Solution

  • public class Solution
extends Object
    2246 - Longest Path With Different Adjacent Characters.

    Hard

    You are given a tree (i.e. a connected, undirected graph that has no cycles) rooted at node 0 consisting of n nodes numbered from 0 to n - 1. The tree is represented by a 0-indexed array parent of size n, where parent[i] is the parent of node i. Since node 0 is the root, parent[0] == -1.

    You are also given a string s of length n, where s[i] is the character assigned to node i.

    Return the length of the longest path in the tree such that no pair of adjacent nodes on the path have the same character assigned to them.

    Example 1:

    Input: parent = [-1,0,0,1,1,2], s = “abacbe”

    Output: 3

    Explanation: The longest path where each two adjacent nodes have different characters in the tree is the path: 0 -> 1 -> 3. The length of this path is 3, so 3 is returned.

    It can be proven that there is no longer path that satisfies the conditions.

    Example 2:

    Input: parent = [-1,0,0,0], s = “aabc”

    Output: 3

    Explanation: The longest path where each two adjacent nodes have different characters is the path: 2 -> 0 -> 3. The length of this path is 3, so 3 is returned.

    Constraints:

    • n == parent.length == s.length
    • 1 <= n <= 105
    • 0 <= parent[i] <= n - 1 for all i >= 1
    • parent[0] == -1
    • parent represents a valid tree.
    • s consists of only lowercase English letters.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • longestPath

        public int longestPath​(int[] parent,
                       String s)