CSE205 Lecture 21

Object-Oriented Programming and Data Structures
Connecting the Dots
(202111)

Transcript

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   CSE 205
   Object-Oriented Programming and
   Data Structures
   Lecture 21: Binary Tree
   Dr. Javier Gonzalez-Sanchez
   javiergs@asu.edu
   javiergs.engineering.asu.edu | javiergs.com
   PERALTA 230U
   Office Hours: By appointment
   

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2. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 2
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   Quiz 05
   § Open Today.
   § You have a week to work
   § A 30 minutes Quiz about data structures (including Trees)
   

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   Nuts and bolts of Binary Trees
   Nodes
   

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4. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 4
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   What is the problem with arrays?
   

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5. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 5
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   I introduce you a List, a Linked List
   

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6. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 6
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   What about this?
   

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7. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 7
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   Binary Tree
   § A non-linear data structure
   § where each node can have 2 children at most.
   § keep the tree sorted
   

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8. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 8
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   Node
   class Node {
   public int value;
   public Node left
   public Node right;
   Node(int value){
   value = value;
   left = null;
   right = null;
   }
   }
   

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9. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 9
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   Tree | insert
   public class Tree {
   public void insert(Node node, int value) {
   if (value < node.value) {
   if (node.left != null) {
   insert(node.left, value);
   } else {
   System.out.println(" Inserted to left");
   node.left = new Node(value);
   }
   } else if (value > node.value) {
   if (node.right != null) {
   insert(node.right, value);
   } else {
   System.out.println(" Inserted to right ");
   node.right = new Node(value);
   }
   }
   }
   

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10. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 10
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    Tree | Example
    public static void main(String args[]) {
    Tree tree = new Tree();
    Node root = new Node(5);
    tree.insert(root, 2);
    tree.insert(root, 4);
    tree.insert(root, 8);
    tree.insert(root, 6);
    tree.insert(root, 7);
    tree.insert(root, 3);
    tree.insert(root, 9);
    tree.traverseLevelOrder();
    }
    }
    

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    Nuts and bolts of Binary Trees
    Traverse
    

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12. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 12
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    Tree | Traverse In Order
    public void traverseInOrder(Node node) {
    if (node != null) {
    traverseInOrder(node.left);
    System.out.print(" " + node.value);
    traverseInOrder(node.right);
    }
    }
    

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13. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 13
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    Tree | Traverse In Order
    

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14. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 14
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    Tree | Traverse Pre Order
    public void traverseInOrder(Node node) {
    if (node != null) {
    System.out.print(" " + node.value);
    traverseInOrder(node.left);
    traverseInOrder(node.right);
    }
    }
    

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15. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 15
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    Tree | Traverse Pre Order
    

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16. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 16
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    Tree | Traverse Post Order
    public void traverseInOrder(Node node) {
    if (node != null) {
    traverseInOrder(node.left);
    traverseInOrder(node.right);
    System.out.print(" " + node.value);
    }
    }
    

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17. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 17
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    Tree | Traverse Post Order
    

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18. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 30
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    Questions
    

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19. jgs
    CSE 205 Object-Oriented Programming and Data Structures
    Javier Gonzalez-Sanchez, Ph.D.
    javiergs@asu.edu
    Fall 2021
    Copyright. These slides can only be used as study material for the class CSE205 at Arizona State University.
    They cannot be distributed or used for another purpose.
    

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