Description: Optimal substructure is a fundamental property in algorithm theory that refers to the ability of a problem to be broken down into smaller, manageable subproblems, whose results can be combined to solve the original problem. This characteristic is essential in dynamic programming and recursion, where the goal is to solve complex problems by dividing them into simpler parts. Optimal substructure implies that the optimal solution to a problem can be constructed from the optimal solutions of its subproblems. This not only facilitates problem-solving but also allows for the reuse of previously computed solutions, which can lead to significant improvements in algorithm efficiency. Identifying optimal substructure is crucial for designing efficient algorithms, as it enables the application of techniques such as memoization and dynamic programming, which optimize execution time by avoiding redundant calculations. In summary, optimal substructure is a key concept underlying many algorithms and problem-solving techniques in computer science, providing a framework for systematically and efficiently tackling a wide range of complex problems.