How do you implement a binary tree?

A binary tree can be implemented using a node class that holds a value and references to left and right child nodes. In languages like Java or Python, you define a class Node with fields for data, left, and right. To insert a value, start at the root and recursively compare the value with the current node’s data: if smaller, go left; if larger, go right; if equal, decide on policy (e.g., ignore or store duplicates). For traversal, use recursion or a stack: in-order (left, root, right) yields sorted order; pre-order (root, left, right) is useful for copying; post-order (left, right, root) for deletion. Each operation runs in O(h) time, where h is the tree height; for a balanced tree, h = O(log n), otherwise O(n).