Package g2001_2100.s2096_step_by_step_directions_from_a_binary_tree_node_to_another

Class Solution

java.lang.Object
g2001_2100.s2096_step_by_step_directions_from_a_binary_tree_node_to_another.Solution
public class Solution extends java.lang.Object
2096 - Step-By-Step Directions From a Binary Tree Node to Another.

Medium

You are given the root of a binary tree with n nodes. Each node is uniquely assigned a value from 1 to n. You are also given an integer startValue representing the value of the start node s, and a different integer destValue representing the value of the destination node t.

Find the shortest path starting from node s and ending at node t. Generate step-by-step directions of such path as a string consisting of only the uppercase letters 'L', 'R', and 'U'. Each letter indicates a specific direction:

  • 'L' means to go from a node to its left child node.
  • 'R' means to go from a node to its right child node.
  • 'U' means to go from a node to its parent node.

Return the step-by-step directions of the shortest path from node s to node t.

Example 1:

Input: root = [5,1,2,3,null,6,4], startValue = 3, destValue = 6

Output: “UURL”

Explanation: The shortest path is: 3 \u2192 1 \u2192 5 \u2192 2 \u2192 6.

Example 2:

Input: root = [2,1], startValue = 2, destValue = 1

Output: “L”

Explanation: The shortest path is: 2 \u2192 1.

Constraints:

  • The number of nodes in the tree is n.
  • 2 <= n <= 105
  • 1 <= Node.val <= n
  • All the values in the tree are unique.
  • 1 <= startValue, destValue <= n
  • startValue != destValue

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    java.lang.String
    getDirections(TreeNode root, int startValue, int destValue)
     

    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

    • getDirections

      public java.lang.String getDirections(TreeNode root, int startValue, int destValue)