Bt-Binary-Tree

Problem 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: ...

Problem You are given a 2D integer array descriptions where descriptions[i] = [parenti, childi, isLefti] indicates that parenti is the parent of childi in a binary tree of unique values. Furthermore, If isLefti == 1, then childi is the left child of parenti. If isLefti == 0, then childi is the right child of parenti. Construct the binary tree described by descriptions and return its root. ...

Problem Implement locking in a binary tree. A binary tree node can be locked or unlocked only if all of its descendants or ancestors are not locked. Design a binary tree node class with the following methods: is_locked, which returns whether the node is locked lock, which attempts to lock the node. If it cannot be locked, then it should return false. Otherwise, it should lock it and return true. unlock, which unlocks the node. If it cannot be unlocked, then it should return false. Otherwise, it should unlock it and return true. You may augment the node to add parent pointers or any other property you would like. You may assume the class is used in a single-threaded program, so there is no need for actual locks or mutexes. Each method should run in O(h), where h is the height of the tree. ...

Problem You are given the root of a binary tree with n nodes where each node in the tree has node.val coins. There are n coins in total throughout the whole tree. In one move, we may choose two adjacent nodes and move one coin from one node to another. A move may be from parent to child, or from child to parent. Return the minimum number of moves required to make every node have exactly one coin. ...

Problem Given a binary tree root and an integer target, delete all the leaf nodes with value target. Note that once you delete a leaf node with value target, if its parent node becomes a leaf node and has the value target, it should also be deleted (you need to continue doing that until you cannot). Examples Example 1: ...

Problem You are given the root of a full binary tree with the following properties: Leaf nodes have either the value 0 or 1, where 0 represents False and 1 represents True. Non-leaf nodes have either the value 2 or 3, where 2 represents the boolean OR and 3 represents the boolean AND. The evaluation of a node is as follows: If the node is a leaf node, the evaluation is the value of the node, i.e. True or False. Otherwise, evaluate the node’s two children and apply the boolean operation of its value with the children’s evaluations. Return the boolean result of evaluating the root node. ...

Problem Implement a function to check if a tree is balanced. Definition Height-balanced binary tree: is defined as a binary tree in which the depth of the two sub-trees of every node never differ by more than 1. Examples Example 1 3 / \ 9 20 / \ 15 7 ...

Problem A path in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequence at most once. Note that the path does not need to pass through the root. The path sum of a path is the sum of the node’s values in the path. Given the root of a binary tree, return the maximum path sum of any non-empty path. ...

Problem Given the root of a binary tree, return the zigzag level order traversal of its nodes’ values. (i.e., from left to right, then right to left for the next level and alternate between). Example Example 1 Tree Traversal Direction 3 -> / \ 9 20 <- / \ 15 7 -> ...

Problem Given two integer arrays inorder and postorder where inorder is the inorder traversal of a binary tree and postorder is the postorder traversal of the same tree, construct and return the binary tree. Example Example 1: 3 / \ 9 20 / \ 15 7 ...