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 Object

2096 - Step-By-Step Directions From a Binary Tree Node to Another.<p>Medium</p> <p>You are given the <code>root</code> of a <strong>binary tree</strong> with <code>n</code> nodes. Each node is uniquely assigned a value from <code>1</code> to <code>n</code>. You are also given an integer <code>startValue</code> representing the value of the start node <code>s</code>, and a different integer <code>destValue</code> representing the value of the destination node <code>t</code>.</p> <p>Find the <strong>shortest path</strong> starting from node <code>s</code> and ending at node <code>t</code>. Generate step-by-step directions of such path as a string consisting of only the <strong>uppercase</strong> letters <code>'L'</code>, <code>'R'</code>, and <code>'U'</code>. Each letter indicates a specific direction:</p> <ul> <li><code>'L'</code> means to go from a node to its <strong>left child</strong> node.</li> <li><code>'R'</code> means to go from a node to its <strong>right child</strong> node.</li> <li><code>'U'</code> means to go from a node to its <strong>parent</strong> node.</li> </ul> <p>Return <em>the step-by-step directions of the <strong>shortest path</strong> from node</em> <code>s</code> <em>to node</em> <code>t</code>.</p> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2021/11/15/eg1.png" alt="" /></p> <p><strong>Input:</strong> root = [5,1,2,3,null,6,4], startValue = 3, destValue = 6</p> <p><strong>Output:</strong> &ldquo;UURL&rdquo;</p> <p><strong>Explanation:</strong> The shortest path is: 3 \u2192 1 \u2192 5 \u2192 2 \u2192 6.</p> <p><strong>Example 2:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2021/11/15/eg2.png" alt="" /></p> <p><strong>Input:</strong> root = [2,1], startValue = 2, destValue = 1</p> <p><strong>Output:</strong> &ldquo;L&rdquo;</p> <p><strong>Explanation:</strong> The shortest path is: 2 \u2192 1.</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the tree is <code>n</code>.</li> <li><code>2 <= n <= 10⁵</code></li> <li><code>1 <= Node.val <= n</code></li> <li>All the values in the tree are <strong>unique</strong>.</li> <li><code>1 <= startValue, destValue <= n</code></li> <li><code>startValue != destValue</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

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