 Sethi–Ullman algorithm

The Sethi–Ullman algorithm is a method used in compiler design for generating efficient code to evaluate expressions, specifically for the purpose of register allocation. Named after authors Rajiv Sethi and Judith D. Ullman, this algorithm is designed to minimize the number of times variables need to be loaded into and stored from memory. ### Key Concepts: 1. **Expression Trees**: The algorithm involves constructing an expression tree, where the internal nodes represent operators and the leaves represent operands (variables).