What are the general plans for divide-and-conquer algorithms

Divide & Conquer is a general algorithm design strategy with a general plan as follows:

(i) DIVIDE: A problem’s instance is divided into several smaller instances of the same problem, ideally of about the same size.

(ii) RECUR: Solve the sub-problem recursively.

(iii) CONQUER: If necessary, the solutions obtained for the smaller instances are combined to get a solution to the original instance.  

Diagram 1 shows the general divide & conquer plan

Figure: Diagram 1.

Advantages of Divide & Conquer technique:

(i) For solving conceptually difficult problems like Tower of Hanoi, divide & conquer is a powerful tool.

(ii) Results in efficient algorithms.

(iii) Results in algorithms that use memory cache efficiently.