Graph Traversal

Depth-First Search (DFS) Problems

Master DFS for your coding interviews. This guide covers common problems, recursive and iterative solutions, and AI-powered hints to help you excel in graph and tree traversal questions.

Recursive In-order Traversal of a Binary Tree

DFS is naturally recursive. A classic example is the in-order traversal of a binary tree, where we visit the left subtree, then the root, then the right subtree.

                            function inOrderTraversal(root) {
                            const result = [];
                            
                            function traverse(node) {
                            if (!node) return;
                            
                            traverse(node.left);
                            result.push(node.val);
                            traverse(node.right);
                            }
                            
                            traverse(root);
                            return result;
                            }
                        

AI Coach Hint: The elegance of DFS lies in its recursive simplicity. However, be mindful of the call stack depth, as a very deep recursion can lead to a stack overflow error. For very large or deep graphs/trees, an iterative approach with an explicit stack might be safer.