Given the root of a binary tree, return the bottom-up level order traversal of its nodes’ values. This means that for each level, starting from the leaf level and moving towards the root, you should collect the node values from left to right.
Given the head of a singly linked list where elements are sorted in ascending order, convert it into a height-balanced binary search tree. A height-balanced binary search tree is one where the depth of the two subtrees of every node never differs by more than 1.
Given the root of a binary tree and an integer targetSum, return all paths from the root to the leaf nodes where the sum of the node values along the path equals the targetSum. A root-to-leaf path is defined as any path that starts from the root and ends at a leaf node. A leaf node is a node that does not have any children.
Given the root of a binary tree, flatten the tree into a ’linked list’ where each node’s right pointer points to the next node in pre-order traversal, and the left pointer of all nodes is null. The ’linked list’ should maintain the same order as a pre-order traversal of the binary tree.
You are given a perfect binary tree where every parent node has two children and all leaves are at the same level. Your task is to populate the ’next’ pointer of each node to point to its next right node. If no such node exists, set the ’next’ pointer to NULL. Initially, all ’next’ pointers are set to NULL.
