Which of the following is a feature of an efficient algorithm?

An efficient algorithm is characterized by its ability to optimize performance, particularly in terms of time and space complexities. The correct choice highlights a key strategy for improving efficiency through the use of techniques like dynamic programming or memoization, which allow the algorithm to store and reuse previously computed results. By reusing solutions, the algorithm avoids the overhead of recalculating values, which can significantly reduce the overall computation time, especially for problems with overlapping subproblems or optimal substructure.

This approach leads to more sophisticated algorithms that can handle complex problems efficiently. For instance, a Fibonacci sequence calculation can be greatly accelerated by storing results of previous computations rather than recalculating them for each recursive call.

In contrast, the other choices either misrepresent characteristics of efficient algorithms or focus on aspects that do not inherently contribute to efficiency. For example, the notion that an algorithm always runs in constant time is unrealistic for many common problems. Similarly, stating that an efficient algorithm only solves simple problems overlooks the capability of algorithms designed to tackle complex tasks efficiently. Lastly, advocating for maximum memory usage in pursuit of speed contradicts the principle of efficiency since it can lead to excessive resource consumption and potential performance degradation in scenarios with limited memory.