lecture13 - Wednesday,May17 BinarySearchTrees...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Wednesday, May 17 th Binary Tree Traversals Using Binary Trees to Evaluate Expressions Binary Search Trees Binary Search Tree Operations Searching for an item Inserting a new item Finding the minimum and maximum items Printing out the items in order Deleting the whole tree
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Binary Tree Traversals  When we process all the nodes in a tree, it’s called a traversal.  There are four common ways to traverse a tree. 1. Pre-order traversal 2. In-order traversal 3. Post-order traversal           4. Level-order traversal Preorder : 1. Process the current node. 2. Process the nodes in the left sub-tree. 3. Process the nodes in the right sub-tree.
Image of page 2
The Preorder Traversal Preorder : 1. Process the current node. 2. Process the nodes in the left sub-tree. 3. Process the nodes in the right sub-tree. By “ process the current node ” we typically mean one of the following: 1. Print the current node’s value out. 1. Search the current node to see if its value matches the one you’re  searching for. 1. Add the current node’s value to a total for the tree 1. Etc…
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
void PreOrder(Node *cur) {     if (cur == NULL)     // if empty, return…          return;     cout << cur->value;        //  Process the  current  node.     PreOrder(cur->left);     //  Process nodes in  left sub-tree .     PreOrder(cur-> right);  //  Process nodes in  left sub-tree . } main() {    Node *root;    …    PreOrder(root); } NULL    “a”   “b”     “c” NULL    “d” NULL NULL NULL     “e” NULL root Output: a Cur points to “a” void PreOrder(Node *cur) {     if (cur == NULL)     // if empty, return…          return;     cout << cur->value;        //  Process the  current  node.     PreOrder(cur->left);     //  Process nodes in  left sub-tree .     PreOrder(cur-> right);  //  Process nodes in  left sub-tree . } Cur points to “b” b The Pre-order Traversal void PreOrder(Node *cur) {     if (cur == NULL)     // if empty, return…          return;     cout << cur->value;        //  Process the  current  node.     PreOrder(cur->left);     //  Process nodes in  left sub-tree .     PreOrder(cur-> right);  //  Process nodes in  left sub-tree . } Cur points to “d” d void PreOrder(Node *cur) {     if (cur == NULL)     // if empty, return…          return;     cout << cur->value;        //  Process the  current  node.
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern