Problem Given a Binary tree where each node has an extra field (node * next), write a function that puts the inorder successor of that node in the next pointer. struct node { int val; struct node * left; struct node * right; struct node * next; } ...
Problem Given the root of a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node’s key. The right subtree of a node contains only nodes with keys greater than the node’s key. Both the left and right subtrees must also be binary search trees. Examples Example 1: ...
Problem Find Inorder Successor in Binary Tree. OR Given a Binary tree, find the inorder successor of a node. Definition See the definition here. Examples Example 1: 10 / \ 5 30 / \ 22 35 ...
Sum of Distances in Tree Problem Problem There is an undirected connected tree with n nodes labeled from 0 to n - 1 and n - 1 edges. You are given the integer n and the array edges where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree. Return an array answer of length n where answer[i] is the sum of the distances between the ith node in the tree and all other nodes. ...
Problem Consider all the leaves of a binary tree, from left to right order, the values of those leaves form a leaf value sequence. graph TD; A(3) --- B(5) & C(1) B --- D(6) & E(2) E --- F(7) & G(4) C --- H(9) & I(8) style D fill:#4682B4,stroke:#333,stroke-width:2px style F fill:#4682B4,stroke:#333,stroke-width:2px style G fill:#4682B4,stroke:#333,stroke-width:2px style H fill:#4682B4,stroke:#333,stroke-width:2px style I fill:#4682B4,stroke:#333,stroke-width:2px ...
Problem Given the root of a binary tree, the level of its root is 1, the level of its children is 2, and so on. Return the smallest level x such that the sum of all the values of nodes at level x is maximal. Opposite of this problem - Minimum Level Sum of a Binary Tree Problem. Examples Example 1: graph TD A(1) --- B(7) & C(0) B --- D(7) & E("-8") ...
Problem You are given the root of a binary tree and an integer distance. A pair of two different leaf nodes of a binary tree is said to be good if the length of the shortest path between them is less than or equal to distance. Return the number of good leaf node pairs in the tree. Examples Example 1: 1 / \ 2 3 \ 4 ...
Vertical Order Traversal of a Binary Tree Problem Problem Given the root of a binary tree, calculate the vertical order traversal of the binary tree. For each node at position (row, col), its left and right children will be at positions (row + 1, col - 1) and (row + 1, col + 1) respectively. The root of the tree is at (0, 0). The vertical order traversal of a binary tree is a list of top-to-bottom orderings for each column index starting from the leftmost column and ending on the rightmost column. There may be multiple nodes in the same row and same column. In such a case, sort these nodes by their values. ...
Problem Given a binary tree, print it in vertical order sum Examples Example 1: ...
Graph - Breadth First Search OR BFS Traversal The Idea Compared to depth first search (DFS), this traversal method prioritizes exploring closer neighbours first. It ensures that all nodes at a similar distance from the starting point are visited before moving on to nodes further away. This creates a wave-like expansion outward, visiting all nodes at a specific distance before progressing to the next layer. Examples Example 1 We can thing of breadth first search as a “wave” walk through the graph. In other words we go level by level, as shown on the picture below. ...