Recursion vs Iteration: How to Pick the Right Approach for Tree Problems

A developer reflecting on a coding interview experience explains why recursion often outperforms iteration when working with recursive data structures like binary trees. When tasked with summing all nodes in a binary tree, an iterative approach using an explicit stack proved lengthy and error-prone compared to a recursive solution. The recursive version mirrors the natural definition of a binary tree, where each node's total equals its value plus the sum of its left and right subtrees, making the code concise and readable. Iteration remains preferable for problems with known-length sequences or when call-stack depth is a concern, but recursion eliminates manual bookkeeping by letting the call stack manage state automatically. A key caution highlighted is always including a base case in recursive functions to prevent infinite loops.