How do you approach a recursive problem?

1. Step 1) Know what your function should do.
2. Step 2) Pick a subproblem and assume your function already works on it.
3. Step 3) Take the answer to your subproblem, and use it to solve for the original problem.
4. Step 4) You have already solved 99\% of the problem.

What are the three things that are required of a recursive program?

Like the robots of Asimov, all recursive algorithms must obey three important laws:

• A recursive algorithm must call itself, recursively.
• A recursive algorithm must have a base case.
• A recursive algorithm must change its state and move toward the base case.

What is a recursive function?

A recursive function is a function that makes calls to itself. It works like the loops we described before, but sometimes it the situation is better to use recursion than loops. Every recursive function has two components: a base case and a recursive step. The base case is usually the smallest input and has an easily verifiable solution.

What are some examples of recursion in programming languages?

However, a few algorithms, (e.g. merge sort, quick sort, etc…) result in optimal time complexity using recursion. One critical requirement of recursive functions is the termination point or base case. Every recursive program must have a base case to make sure that the function will terminate.

Why do we need to know recursion?

And knowing recursion will also give you a new way of thinking, which is dividing the problem into multiple instances of the same problem, which will help you understanding techniques like dynamic programming, backtracking… See you in the first lecture!

How can recursion be used to solve a puzzle easily?

Mathematically, recursion helps to solve a few puzzles easily. In a party of N people, each person will shake her/his hand with each other person only once. In total how many hand-shakes would happen? It can be solved in different ways; graphs, recursions, etc. Let us see how recursively it can be solved. There are N persons.