What is one characteristic of an efficient algorithm?

An efficient algorithm is characterized by its ability to optimize resources, which include both time and space. This means that it performs its operations in a manner that minimizes execution time while also using the least amount of memory necessary. An algorithm that achieves low time complexity ensures that it can process large inputs quickly, while low space complexity ensures it doesn’t use excessive memory. This efficiency is essential in practice, especially as input sizes grow, making it feasible to execute complex tasks within reasonable limits.

While the other characteristics mentioned, such as ease of understanding or having a constant runtime, are valuable, they do not specifically define efficiency in the context of algorithm analysis. For instance, an algorithm can be straightforward to implement but still perform poorly in terms of time and space, thereby not being efficient. Therefore, the essence of efficiency inherently relates to optimizing resource consumption.