What is meant by the phrase "divide and conquer"?

Divide and conquer is a problem-solving strategy wherein a complex problem is broken down into simpler sub-problems. These sub-problems are then solved independently and combined to form the final solution for the original problem. This strategy is used in various fields such as computer science, mathematics, and engineering.

One common example of divide-and-conquer in computer science is a sorting algorithm called Merge Sort. Here's how the process works: 1. Divide the unsorted list into two equal halves. 2. Recursively apply Merge Sort to each of the halves until the sub-lists are of size 1 or 2. These small sub-lists are trivial to sort. 3. Merge the two sorted sub-lists back together to produce a single sorted list. The merging process itself consists of iterating through the two sub-lists, comparing the elements from each list, and adding the smallest one to the final sorted list until both sub-lists have been fully processed. This way, the final list will contain all the elements from the input list sorted in the required order. By breaking down the initial list into smaller sub-problems and solving them independently, Merge Sort efficiently sorts a large list in a divide-and-conquer manner.