What is the strategy pattern, and how does DI replace standard strategy implementation?

The Strategy Pattern defines a family of algorithms. DI automates the selection and provisioning of these algorithms.

Instead of a consumer manually instantiating new QuickSort() or new MergeSort(), the DI container provides an IEnumerable<ISortStrategy>. The consumer can loop through them or a factory can resolve the specific strategy based on a context variable (like array size).