Recursion

        This is the second time I write the blog that is about Recursion. Throughout the continuous learning according to this topic, I am more familiar with it. Besides knowing what it is, I learn how to use it now.

        A1 gives us the opportunity for practicing of using recursion. We need to solve the challenging problem by applying the structure of recursion. Also, it is very helpful to work with classmates. We can help each other on working it. 

        In addition, “Tree” is the good example. Form the structure of Tree, it is really like a family. There is a root, which is also the original parent and its children also have their children. In the methods of Tree, all returns are only one line owing to comprehensive and they clearly show the abstract solution. For example, count is the method for counting the nodes in the Tree. The function is “return 1 + sum([count(n) for n in t.children]). It counts all the parents and leafs. If the n is also the parents, it needs to call the function itself. Also, we could use the structure of Tree to do the calculation: preorder, inorder and postorder.

        Recursion is very important. The main benefits are these two: firstly, the program using recursion functions is obviously clearer, simpler, shorter, and easier to understand. Secondly, it directly reflects the algorithm. All in all, I prefer recursion to iteration.