Binary Trees Explained in 4 Minutes!

Key Takeaways

Today we will talk about binary trees. Now, I know, on a surface level, this concept may seem quite tough, but follow along with me, and you'll realize it's a fairly simple and basic concept. So, let's go ahead and understand the topic. Now, what is a binary tree? Imagine you have a tree. This tree has a trunk, which we call the root, and branches that go down. Now, a binary tree is a little special. Each branch can have only two children. Each note can have only two children. When we talk about trees in computer programming, we call this structure a binary tree. Each node stores data and links its left and right branches. So, what is a node? A node is a point or element in our tree, and each node has three things: data that stores a value: the left child, which is on the left side of the note, and the right child, which is on the right side of the note. For example, if a node is 10, then its data is 10. Its left child is five and its right child can be 20. So now if we talk about the structure of a binary tree or if we want to think of a binary tree in the form of a tree, then it will look something like this. Here 10 is the root node. To the left of 10, we have the left child five and to the right, we have the right child 20. To the left of five, we have three and to the right, we have seven. To the left of 20, we have 15 and to the right, we have 25. And now that you have understood what a binary tree is, let us see the code example of this thing. That means if we want to code a binary tree in Python, then first of all we will create a Node class in which the data, left and right child will be stored. This is a very simple code. When you create an object of this node, your data will be stored in that node. Now we create its binary tree. That means, as I told earlier, our 10 is the root, five is the left child and 20 is the right child. If we implement this in the code, then it will look something like this. Now we have a binary tree. Now that our binary tree is created, the question that comes to our mind is how do we traverse this tree. Traversal means visiting the notes of the tree in a specific order. Traversal can be done in three ways in a binary tree. Pre- order traversal, in-order reversal and post-order reversal. In pre-order we first visit the root, then the left child, then the right child. The result of this reversal will be 10 5 3 7 then 20 15 25. In in-order reversal we first visit the left child, then the root note, then the right child. The result of this traversal will be 3 5 7 10 15 20 25. And in post-order we visit the left child, then the right child, then the root note. The result of this reversal will be 3 7 5 15 25 20 10. Meaning, pre-order is when we first write the root, then the left child and the right child. In-order is when we go to the left child, root and right child. And post-order is when we visit the left child, right child and then Coming back to the root, how do we search in a binary tree? So imagine we have a binary tree created and now we need to search for a particular value within it. So how can we do that? Let's look at the code. Suppose we need to search for seven in our binary tree. Its code will be [music]. This code will check whether seven is in our tree or not. Now, when we talk about the use of binary trees, they are very important in programming and help us do many things efficiently. For example, this creates our binary search tree when we need to search quickly; heap when we need the minimum or maximum element quickly; and expression trees when we need to evaluate mathematical expressions. Now you must have understood what a binary tree is and how it works. You now know that in a binary tree, each note has only two children, and we can search and traverse within them. This concept helps you [music]. Understanding complex and creating your own trees is something I understand. The concept of binary trees is a little complicated and implement it in your own code, it becomes quite easy, I hope you understand it, do let us know in the comments if you want us to simplify it further, happy coding