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Computer notes - Binary Search Tree with Strings

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Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. This should not come as a surprise if you consider how we built the BST. For a given node, values less than the info in the node were all in the left subtree and values greater or equal were in the right.

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• End of lecture 14
• Start lecture 16
• End of lecture 15
• Computer notes - Binary Search Tree with Strings

1. 1. Class No.15 Data Structures http://ecomputernotes.com
2. 2. Level-order Traversal <ul><li>There is yet another way of traversing a binary tree that is not related to recursive traversal procedures discussed previously. </li></ul><ul><li>In level-order traversal, we visit the nodes at each level before proceeding to the next level. </li></ul><ul><li>At each level, we visit the nodes in a left-to-right order. </li></ul>http://ecomputernotes.com
3. 3. Level-order Traversal Level-order: 14 4 15 3 9 18 7 16 20 5 17 http://ecomputernotes.com 14 4 9 7 3 5 15 18 16 20 17
4. 4. Level-order Traversal <ul><li>How do we do level-order traversal? </li></ul><ul><li>Surprisingly, if we use a queue instead of a stack, we can visit the nodes in level-order. </li></ul><ul><li>Here is the code for level-order traversal: </li></ul>http://ecomputernotes.com
5. 5. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
6. 6. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
7. 7. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
8. 8. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
9. 9. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
10. 10. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
11. 11. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
12. 12. Level-order Traversal <ul><li>void levelorder(TreeNode<int>* treeNode) </li></ul><ul><li>{ </li></ul><ul><li>Queue<TreeNode<int>* > q; </li></ul><ul><li>if( treeNode == NULL ) return; </li></ul><ul><li>q.enqueue( treeNode); </li></ul><ul><li>while( !q.empty() ) </li></ul><ul><li>{ </li></ul><ul><li>treeNode = q.dequeue(); </li></ul><ul><li>cout << *(treeNode->getInfo()) << &quot; &quot;; </li></ul><ul><li>if(treeNode->getLeft() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getLeft()); </li></ul><ul><li>if(treeNode->getRight() != NULL ) </li></ul><ul><li>q.enqueue( treeNode->getRight()); </li></ul><ul><li>} </li></ul><ul><li>cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
13. 13. Level-order Traversal Queue: 14 Output: 14 http://ecomputernotes.com 4 9 7 3 5 15 18 16 20 17
14. 14. Level-order Traversal Queue: 4 15 Output: 14 14 4 15 http://ecomputernotes.com 9 7 3 5 18 16 20 17
15. 15. Level-order Traversal Queue: 15 3 9 Output: 14 4 14 4 9 3 15 http://ecomputernotes.com 7 5 18 16 20 17
16. 16. Level-order Traversal Queue: 3 9 18 Output: 14 4 15 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
17. 17. Level-order Traversal Queue: 9 18 Output: 14 4 15 3 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
18. 18. Level-order Traversal Queue: 18 7 Output: 14 4 15 3 9 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
19. 19. Level-order Traversal Queue: 7 16 20 Output: 14 4 15 3 9 18 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
20. 20. Level-order Traversal Queue: 16 20 5 Output: 14 4 15 3 9 18 7 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
21. 21. Level-order Traversal Queue: 20 5 17 Output: 14 4 15 3 9 18 7 16 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
22. 22. Level-order Traversal Queue: 5 17 Output: 14 4 15 3 9 18 7 16 20 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
23. 23. Level-order Traversal Queue: 17 Output: 14 4 15 3 9 18 7 16 20 5 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
24. 24. Level-order Traversal Queue: Output: 14 4 15 3 9 18 7 16 20 5 17 14 4 9 7 3 5 15 18 16 20 17 http://ecomputernotes.com
25. 25. Storing other Type of Data <ul><li>The examples of binary trees so far have been storing integer data in the tree node. </li></ul><ul><li>This is surely not a requirement. Any type of data can be stored in a tree node. </li></ul><ul><li>Here, for example, is the C++ code to build a tree with character strings. </li></ul>http://ecomputernotes.com
26. 26. Binary Search Tree with Strings <ul><li>void wordTree() </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* root = new TreeNode<char>(); </li></ul><ul><li>static char* word[] = &quot;babble&quot;, &quot;fable&quot;, &quot;jacket&quot;, &quot;backup&quot;, &quot;eagle&quot;,&quot;daily&quot;,&quot;gain&quot;,&quot;bandit&quot;,&quot;abandon&quot;, </li></ul><ul><li> &quot;abash&quot;,&quot;accuse&quot;,&quot;economy&quot;,&quot;adhere&quot;,&quot;advise&quot;,&quot;cease&quot;, </li></ul><ul><li> &quot;debunk&quot;,&quot;feeder&quot;,&quot;genius&quot;,&quot;fetch&quot;,&quot;chain&quot;, NULL}; </li></ul><ul><li>root->setInfo( word[0] ); </li></ul><ul><li>for(i=1; word[i]; i++ ) </li></ul><ul><li>insert(root, word[i] ); </li></ul><ul><li>inorder( root ); cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
27. 27. Binary Search Tree with Strings <ul><li>void wordTree() </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* root = new TreeNode<char>(); </li></ul><ul><li>static char* word[] = &quot;babble&quot;, &quot;fable&quot;, &quot;jacket&quot;, &quot;backup&quot;, &quot;eagle&quot;,&quot;daily&quot;,&quot;gain&quot;,&quot;bandit&quot;,&quot;abandon&quot;, </li></ul><ul><li> &quot;abash&quot;,&quot;accuse&quot;,&quot;economy&quot;,&quot;adhere&quot;,&quot;advise&quot;,&quot;cease&quot;, </li></ul><ul><li> &quot;debunk&quot;,&quot;feeder&quot;,&quot;genius&quot;,&quot;fetch&quot;,&quot;chain&quot;, NULL}; </li></ul><ul><li>root->setInfo( word[0] ); </li></ul><ul><li>for(i=1; word[i]; i++ ) </li></ul><ul><li>insert(root, word[i] ); </li></ul><ul><li>inorder( root ); cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
28. 28. Binary Search Tree with Strings <ul><li>void wordTree() </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* root = new TreeNode<char>(); </li></ul><ul><li>static char* word[] = &quot;babble&quot;, &quot;fable&quot;, &quot;jacket&quot;, &quot;backup&quot;, &quot;eagle&quot;,&quot;daily&quot;,&quot;gain&quot;,&quot;bandit&quot;,&quot;abandon&quot;, </li></ul><ul><li> &quot;abash&quot;,&quot;accuse&quot;,&quot;economy&quot;,&quot;adhere&quot;,&quot;advise&quot;,&quot;cease&quot;, </li></ul><ul><li> &quot;debunk&quot;,&quot;feeder&quot;,&quot;genius&quot;,&quot;fetch&quot;,&quot;chain&quot;, NULL}; </li></ul><ul><li>root->setInfo( word[0] ); </li></ul><ul><li>for(i=1; word[i]; i++ ) </li></ul><ul><li>insert(root, word[i] ); </li></ul><ul><li>inorder( root ); cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
29. 29. Binary Search Tree with Strings <ul><li>void wordTree() </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* root = new TreeNode<char>(); </li></ul><ul><li>static char* word[] = &quot;babble&quot;, &quot;fable&quot;, &quot;jacket&quot;, &quot;backup&quot;, &quot;eagle&quot;,&quot;daily&quot;,&quot;gain&quot;,&quot;bandit&quot;,&quot;abandon&quot;, </li></ul><ul><li> &quot;abash&quot;,&quot;accuse&quot;,&quot;economy&quot;,&quot;adhere&quot;,&quot;advise&quot;,&quot;cease&quot;, </li></ul><ul><li> &quot;debunk&quot;,&quot;feeder&quot;,&quot;genius&quot;,&quot;fetch&quot;,&quot;chain&quot;, NULL}; </li></ul><ul><li>root->setInfo( word[0] ); </li></ul><ul><li>for(i=1; word[i]; i++ ) </li></ul><ul><li>insert(root, word[i] ); </li></ul><ul><li>inorder( root ); cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
30. 30. Binary Search Tree with Strings <ul><li>void wordTree() </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* root = new TreeNode<char>(); </li></ul><ul><li>static char* word[] = &quot;babble&quot;, &quot;fable&quot;, &quot;jacket&quot;, &quot;backup&quot;, &quot;eagle&quot;,&quot;daily&quot;,&quot;gain&quot;,&quot;bandit&quot;,&quot;abandon&quot;, </li></ul><ul><li> &quot;abash&quot;,&quot;accuse&quot;,&quot;economy&quot;,&quot;adhere&quot;,&quot;advise&quot;,&quot;cease&quot;, </li></ul><ul><li> &quot;debunk&quot;,&quot;feeder&quot;,&quot;genius&quot;,&quot;fetch&quot;,&quot;chain&quot;, NULL}; </li></ul><ul><li>root->setInfo( word[0] ); </li></ul><ul><li>for(i=1; word[i]; i++ ) </li></ul><ul><li>insert(root, word[i] ); </li></ul><ul><li>inorder( root ); cout << endl; </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
31. 31. Binary Search Tree with Strings <ul><li>void insert(TreeNode<char>* root, char* info) </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* node = new TreeNode<char>(info); </li></ul><ul><li>TreeNode<char> *p, *q; </li></ul><ul><li>p = q = root; </li></ul><ul><li>while( strcmp(info, p->getInfo()) != 0 && q != NULL ) </li></ul><ul><li>{ </li></ul><ul><li>p = q; </li></ul><ul><li>if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>q = p->getLeft(); </li></ul><ul><li>else </li></ul><ul><li>q = p->getRight(); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
32. 32. Binary Search Tree with Strings <ul><li>void insert(TreeNode<char>* root, char* info) </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* node = new TreeNode<char>(info); </li></ul><ul><li>TreeNode<char> *p, *q; </li></ul><ul><li>p = q = root; </li></ul><ul><li>while( strcmp(info, p->getInfo()) != 0 && q != NULL ) </li></ul><ul><li>{ </li></ul><ul><li>p = q; </li></ul><ul><li>if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>q = p->getLeft(); </li></ul><ul><li>else </li></ul><ul><li>q = p->getRight(); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
33. 33. Binary Search Tree with Strings <ul><li>void insert(TreeNode<char>* root, char* info) </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* node = new TreeNode<char>(info); </li></ul><ul><li>TreeNode<char> *p, *q; </li></ul><ul><li>p = q = root; </li></ul><ul><li>while( strcmp(info, p->getInfo()) != 0 && q != NULL ) </li></ul><ul><li>{ </li></ul><ul><li>p = q; </li></ul><ul><li>if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>q = p->getLeft(); </li></ul><ul><li>else </li></ul><ul><li>q = p->getRight(); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
34. 34. Binary Search Tree with Strings <ul><li>void insert(TreeNode<char>* root, char* info) </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* node = new TreeNode<char>(info); </li></ul><ul><li>TreeNode<char> *p, *q; </li></ul><ul><li>p = q = root; </li></ul><ul><li>while( strcmp(info, p->getInfo()) != 0 && q != NULL ) </li></ul><ul><li>{ </li></ul><ul><li>p = q; </li></ul><ul><li>if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>q = p->getLeft(); </li></ul><ul><li>else </li></ul><ul><li>q = p->getRight(); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
35. 35. Binary Search Tree with Strings <ul><li>void insert(TreeNode<char>* root, char* info) </li></ul><ul><li>{ </li></ul><ul><li>TreeNode<char>* node = new TreeNode<char>(info); </li></ul><ul><li>TreeNode<char> *p, *q; </li></ul><ul><li>p = q = root; </li></ul><ul><li>while( strcmp(info, p->getInfo()) != 0 && q != NULL ) </li></ul><ul><li>{ </li></ul><ul><li>p = q; </li></ul><ul><li>if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>q = p->getLeft(); </li></ul><ul><li>else </li></ul><ul><li>q = p->getRight(); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
36. 36. Binary Search Tree with Strings <ul><li>if( strcmp(info, p->getInfo()) == 0 ){ </li></ul><ul><li>cout << &quot;attempt to insert duplicate: &quot; << *info </li></ul><ul><li><< endl; </li></ul><ul><li>delete node; </li></ul><ul><li>} </li></ul><ul><li>else if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>p->setLeft( node ); </li></ul><ul><li>else </li></ul><ul><li>p->setRight( node ); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
37. 37. Binary Search Tree with Strings <ul><li>if( strcmp(info, p->getInfo()) == 0 ){ </li></ul><ul><li>cout << &quot;attempt to insert duplicate: &quot; << *info </li></ul><ul><li><< endl; </li></ul><ul><li>delete node; </li></ul><ul><li>} </li></ul><ul><li>else if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>p->setLeft( node ); </li></ul><ul><li>else </li></ul><ul><li>p->setRight( node ); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
38. 38. Binary Search Tree with Strings <ul><li>if( strcmp(info, p->getInfo()) == 0 ){ </li></ul><ul><li>cout << &quot;attempt to insert duplicate: &quot; << *info </li></ul><ul><li><< endl; </li></ul><ul><li>delete node; </li></ul><ul><li>} </li></ul><ul><li>else if( strcmp(info, p->getInfo()) < 0 ) </li></ul><ul><li>p->setLeft( node ); </li></ul><ul><li>else </li></ul><ul><li>p->setRight( node ); </li></ul><ul><li>} </li></ul>http://ecomputernotes.com 
39. 39. Binary Search Tree with Strings <ul><li>Output: </li></ul><ul><ul><li>abandon </li></ul></ul><ul><ul><li>abash </li></ul></ul><ul><ul><li>accuse </li></ul></ul><ul><ul><li>adhere </li></ul></ul><ul><ul><li>advise </li></ul></ul><ul><ul><li>babble </li></ul></ul><ul><ul><li>backup </li></ul></ul><ul><ul><li>bandit </li></ul></ul><ul><ul><li>cease </li></ul></ul><ul><ul><li>chain </li></ul></ul><ul><ul><li>daily </li></ul></ul><ul><ul><li>debunk </li></ul></ul><ul><ul><li>eagle </li></ul></ul><ul><ul><li>economy </li></ul></ul><ul><ul><li>fable </li></ul></ul><ul><ul><li>feeder </li></ul></ul><ul><ul><li>fetch </li></ul></ul><ul><ul><li>gain </li></ul></ul><ul><ul><li>genius </li></ul></ul><ul><ul><li>jacket </li></ul></ul>http://ecomputernotes.com
40. 40. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul>http://ecomputernotes.com
41. 41. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul><ul><li>This should not come as a surprise if you consider how we built the BST. </li></ul>http://ecomputernotes.com
42. 42. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul><ul><li>This should not come as a surprise if you consider how we built the BST. </li></ul><ul><li>For a given node, values less than the info in the node were all in the left subtree and values greater or equal were in the right. </li></ul>http://ecomputernotes.com
43. 43. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul><ul><li>This should not come as a surprise if you consider how we built the BST. </li></ul><ul><li>For a given node, values less than the info in the node were all in the left subtree and values greater or equal were in the right. </li></ul><ul><li>Inorder prints the left subtree, then the node finally the right subtree. </li></ul>http://ecomputernotes.com
44. 44. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul><ul><li>This should not come as a surprise if you consider how we built the BST. </li></ul><ul><li>For a given node, values less than the info in the node were all in the left subtree and values greater or equal were in the right. </li></ul><ul><li>Inorder prints the left subtree, then the node finally the right subtree. </li></ul><ul><li>Building a BST and doing an inorder traversal leads to a sorting algorithm. </li></ul>http://ecomputernotes.com
45. 45. Binary Search Tree with Strings <ul><li>abandon </li></ul><ul><li>abash </li></ul><ul><li>accuse </li></ul><ul><li>adhere </li></ul><ul><li>advise </li></ul><ul><li>babble </li></ul><ul><li>backup </li></ul><ul><li>bandit </li></ul><ul><li>cease </li></ul><ul><li>chain </li></ul><ul><li>daily </li></ul><ul><li>debunk </li></ul><ul><li>eagle </li></ul><ul><li>economy </li></ul><ul><li>fable </li></ul><ul><li>feeder </li></ul><ul><li>fetch </li></ul><ul><li>gain </li></ul><ul><li>genius </li></ul><ul><li>jacket </li></ul><ul><li>Notice that the words are sorted in increasing order when we traversed the tree in inorder manner. </li></ul><ul><li>This should not come as a surprise if you consider how we built the BST. </li></ul><ul><li>For a given node, values less than the info in the node were all in the left subtree and values greater or equal were in the right. </li></ul><ul><li>Inorder prints the left subtree, then the node finally the right subtree. </li></ul><ul><li>Building a BST and doing an inorder traversal leads to a sorting algorithm. </li></ul>http://ecomputernotes.com
46. 46. Deleting a node in BST <ul><li>As is common with many data structures, the hardest operation is deletion. </li></ul><ul><li>Once we have found the node to be deleted, we need to consider several possibilities. </li></ul><ul><li>If the node is a leaf , it can be deleted immediately. </li></ul>http://ecomputernotes.com
47. 47. Deleting a node in BST <ul><li>If the node has one child, the node can be deleted after its parent adjusts a pointer to bypass the node and connect to inorder successor. </li></ul>http://ecomputernotes.com 6 2 4 3 1 8
48. 48. Deleting a node in BST <ul><li>The inorder traversal order has to be maintained after the delete. </li></ul> http://ecomputernotes.com 6 2 4 3 1 8 6 2 4 3 1 8
49. 49. Deleting a node in BST <ul><li>The inorder traversal order has to be maintained after the delete. </li></ul>  http://ecomputernotes.com 6 2 4 3 1 8 6 2 4 3 1 8 6 2 3 1 8
50. 50. Deleting a node in BST <ul><li>The complicated case is when the node to be deleted has both left and right subtrees. </li></ul><ul><li>The strategy is to replace the data of this node with the smallest data of the right subtree and recursively delete that node. </li></ul>http://ecomputernotes.com
51. 51. Deleting a node in BST <ul><li>Delete(2): locate inorder successor </li></ul>Inorder successor http://ecomputernotes.com 6 2 5 3 1 8 4
52. 52. Deleting a node in BST <ul><li>Delete(2): locate inorder successor </li></ul>Inorder successor <ul><li>Inorder successor will be the left-most node in the right subtree of 2. </li></ul><ul><li>The inorder successor will not have a left child because if it did, that child would be the left-most node. </li></ul>http://ecomputernotes.com 6 2 5 3 1 8 4
53. 53. Deleting a node in BST <ul><li>Delete(2): copy data from inorder successor </li></ul> http://ecomputernotes.com 6 2 5 3 1 8 4 6 3 5 3 1 8 4
54. 54. Deleting a node in BST <ul><li>Delete(2): remove the inorder successor </li></ul>  http://ecomputernotes.com 6 2 5 3 1 8 4 6 3 5 3 1 8 4 6 3 5 3 1 8 4
55. 55. Deleting a node in BST <ul><li>Delete(2) </li></ul>  http://ecomputernotes.com 6 3 5 4 1 8 6 3 5 3 1 8 4