Binary Search Tree 1.0. Generated by Doxygen Mon Jun :12:39

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1 Binary Search Tree 1.0 Generated by Doxygen Mon Jun :12:39

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3 Contents 1 Binary Search Tree Program Introduction Data Structure Index Data Structures File Index File List Data Structure Documentation BST Struct Reference Detailed Description Field Documentation data left right File Documentation bst.c File Reference Detailed Description Function Documentation createnewnode deletenode main traversebst Variable Documentation root

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5 Chapter 1 Binary Search Tree Program 1.1 Introduction A simple program to create a Binary Search Tree. This will also make me comfortable with using Doxygen. This is really comfortable. I can also generate a custom list as follows. Item1 Item2 Item3 Item4 I can also add formulae like the following one. (x 2 x 1 ) 2 + (y 2 y 1 ) 2 I can also insert an image as follows. Figure 1.1: image-binary_tree And also create external links like this.

6 2 Binary Search Tree Program Author Milind G. Padalkar Date 26-Oct-2010

7 Chapter 2 Data Structure Index 2.1 Data Structures Here are the data structures with brief descriptions: BST (An ADT for Binary Search Tree )

8 4 Data Structure Index

9 Chapter 3 File Index 3.1 File List Here is a list of all documented files with brief descriptions: bst.c (A simple program to create a Binary Search Tree. This will also make me comfortable with using Doxygen )

10 6 File Index

11 Chapter 4 Data Structure Documentation 4.1 BST Struct Reference An ADT for Binary Search Tree. Collaboration diagram for BST: BST + left + data + right right left Data Fields struct BST left int data struct BST right Detailed Description An ADT for Binary Search Tree. This ADT consists of a link to the left subtree, data at the current vertex & a link to the right subtree. Definition at line 38 of file bst.c.

12 8 Data Structure Documentation Field Documentation int data Data at the current node of the BST. Definition at line 40 of file bst.c struct BST left A pointer to the left subtree. Definition at line 39 of file bst.c struct BST right A pointer to the right subtree. Definition at line 41 of file bst.c. The documentation for this struct was generated from the following file: bst.c

13 Chapter 5 File Documentation 5.1 bst.c File Reference A simple program to create a Binary Search Tree. This will also make me comfortable with using Doxygen. #include <stdio.h> #include <stdlib.h> Include dependency graph for bst.c: bst.c stdio.h stdlib.h Data Structures struct BST An ADT for Binary Search Tree. Functions void createnewnode () Function to create a new node.

14 10 File Documentation void traversebst (struct BST curnode) Function to traverse the BST. void deletenode () Function to delete a particular node from the BST. int main (int argc, char argv) The main function. Should not be passed any arguments. Variables struct BST root = NULL This is pointer to the root node Detailed Description A simple program to create a Binary Search Tree. This will also make me comfortable with using Doxygen. Definition in file bst.c Function Documentation void createnewnode ( ) Function to create a new node. When called, this function creates a new node. The new nodes left and right pointers are set to NULL and data is set to the value entered by the user. Once the new node is ready, it needs to be attached at the proper position in the tree. So, the root node is checked. If it is NULL, then the newly created node is assigned to the root. IF the root is not NULL, then current node pointer is associated to the root. Further, the value in the newly created node is checked iteratively with the value at the current node & accordingly the following operations are carried out. If newnode->data <= curnode->data : Assign newnode to curnode & break if curnode->left is NULL, else assign curnode to curnode->left i.e. move to the left subtree. If newnode->data > curnode->data : Assign newnode to curnode & break if curnode->right is NULL, else assign curnode to curnode->right i.e. move to the right subtree. Parameters NULL Returns void. A newly created node is attached at the proper place to the Binary Search Tree. Prints a message New node creation & attachment successful on the command-line. See also traversebst(), deletenode(), main().

15 5.1 bst.c File Reference 11 Definition at line 125 of file bst.c. { struct BST *newnode = ( struct BST * )malloc( sizeof( struct BST ) ); newnode->left = NULL; newnode->right = NULL; printf( "\nenter the value of the new node. : " ); scanf( "%d", &newnode->data ); struct BST *curnode; if( root==null ){ root = newnode; curnode = root; while( 1 ){ if( newnode->data <= curnode->data ){ if( curnode->left == NULL ){ curnode->left = newnode; break; curnode = curnode->left; if( curnode->right == NULL ){ curnode->right = newnode; break; curnode = curnode->right; printf( "\nnew node creation & attachment successful.\n" ); Here is the caller graph for this function: createnewnode main void deletenode ( ) Function to delete a particular node from the BST. This function will ask the user to enter a value (temp_val) to be deleted. The tree will be first searched for this value. If found, it will lead to the the following conditions. A particular node has no childern. So it can be simply deleted & its parent s reference can be set to null.

16 12 File Documentation A particular node has only child-node. In this case, the parent s pointer is assigned to the only child of the current node. A particular node has both children. In this case, the parent s pointer is assigned to the left-child s rightmost node. If this rightmost node has a left child, then it takes the position of the rightmost node. If the rightmost node comes out to be the current node s left child, then simply assign the parent s pointer is directly assigned to this node & the current node can be removed. Parameters Returns NULL. No parameters are passed to this function. void. The command-line prints message on successful deletion of the given node. It also prints the contents of the BST after deletion operation. See also createnewnode(), traversebst(), main(). Definition at line 185 of file bst.c. { int temp_val; printf( "Enter the value of the node to be deleted : " ); scanf( "%d", &temp_val ); struct BST *parentnode = NULL; struct BST *curnode = root ; int found = 0; while( root!=null ){ if( temp_val == curnode->data ){ found = 1; break; parentnode = curnode; if( temp_val < curnode->data ){ if( curnode->left==null ){ break; curnode = curnode->left; if( curnode->right==null ){ break; curnode = curnode->right; if( found==0 ){ printf( "\nnode does not exist. \n" ); //printf( "\nnode %d found. \n", curnode->data ); if( ( curnode->left==null ) && ( curnode->right==null ) ){ if( parentnode!=null ){ if( curnode == parentnode->left ){ parentnode->left = NULL; parentnode->right = NULL;

17 5.1 bst.c File Reference 13 \n" ); root = NULL; free( curnode ); printf( "Node deleted successfully. Modified contents are traversebst( root ); printf( "\n" ); if( ( ( curnode->left!=null ) && ( curnode->right==null ) ) ( ( curnode->left==null ) && ( curnode->right!=null ) ) ){ struct BST *child; if( curnode->left!=null ){ child = curnode->left; child = curnode->right; if( parentnode!=null ){ if( curnode == parentnode->left ){ parentnode->left = child; parentnode->right = child; root = child; free( curnode ); printf( "Node deleted successfully. Modified contents are \n" ); traversebst( root ); printf( "\n" ); if( ( curnode->left!=null ) && ( curnode->right!=null ) ){ struct BST *rightmpar = curnode; struct BST *rightmost = curnode->left; while( rightmost->right!=null ){ rightmpar = rightmost; rightmost=rightmost->right; if( rightmost!= curnode->left ){ if( rightmost->left!=null ){ rightmpar->right = rightmost->left; rightmpar->right = NULL; if( parentnode!=null ){ if( curnode == parentnode->left ){ parentnode->left = rightmost; parentnode->right = rightmost; root = rightmost; if( rightmost!= curnode->left ){ rightmost->left = curnode->left; rightmost->right = curnode->right; free( curnode );

18 14 File Documentation \n" ); printf( "Node deleted successfully. Modified contents are traversebst( root ); printf( "\n" ); Here is the call graph for this function: deletenode traversebst Here is the caller graph for this function: deletenode main int main ( int argc, char argv ) The main function. Should not be passed any arguments. This is the main function of the Binary Search Tree Creation Program. Parameters Returns argc Number of arguments passed to the executable. argv A Pointer to every string passed as the argument to the executable. 0 if program exits normally. Negative if forced to exit before reaching the end. The value of an integer ch, which stores the choice entered by the user, is switched over a loop and the following operations are performed depending on its value. ch = 1 => Create node operation is selected.

19 5.1 bst.c File Reference 15 ch = 2 => Delete node operation is selected. ch = 3 => Tree traversal is selected. ch = 4 => Exit See also createnewnode(), traversebst(), deletenode(). Definition at line 67 of file bst.c. int ch; do{ while( ch!=4 ); { printf( "\nenter Choice:" ); printf( "\n1. Create a node" ); printf( "\n2. Delete a node" ); printf( "\n3. Traverse the tree" ); printf( "\n4. Exit\nEnter Choice : " ); scanf( "%d", &ch ); switch( ch ){ case 1: createnewnode(); break; case 2: deletenode(); break; case 3:{ if( root==null ){ printf( "No nodes exist.\n" ); traversebst( root ); printf( "\n" ); break; case 4: break; default: printf( "Invalid Choice. \n" ); break; return( 0 );

20 16 File Documentation Here is the call graph for this function: createnewnode main deletenode traversebst void traversebst ( struct BST curnode ) Function to traverse the BST. This function performs inorder traversal of the Binary Search Tree. It is a recursive function. Therefore, the argument it takes is a pointer to the starting node of the sub-tree to be traversed. Hence, when we want to traverse the complete tree, the pointer to the root node is passed as the argument to this function. The inorder traversal is performed as follows. For any given node, first visit its left sub-tree ( this is recursive ). When the left sub-tree is completely traversed, print the value at the current node. Finally, visit the right sub-tree ( even this is recursive ). Parameters Returns See also curnode is Pointer to the starting node of the sub-tree / tree to be traversed. void. The command-line prints the value at the various nodes in accordance to inorder traversal. createnewnode(), deletenode(), main(). Definition at line 174 of file bst.c. { if( curnode ){ traversebst( curnode->left ); printf( "%d ", curnode->data ); traversebst( curnode->right );

21 5.1 bst.c File Reference 17 Here is the caller graph for this function: deletenode traversebst main Variable Documentation struct BST root = NULL This is pointer to the root node. This node pointer is empty initially. The value of the first input variable is assigned to the root node. Later, other nodes are created according to the property of the Binary Search Tree. Definition at line 48 of file bst.c.

22 Index BST, 7 data, 8 left, 8 right, 8 bst.c, 9 createnewnode, 10 deletenode, 11 main, 14 root, 17 traversebst, 16 createnewnode bst.c, 10 data BST, 8 deletenode bst.c, 11 left BST, 8 main bst.c, 14 right BST, 8 root bst.c, 17 traversebst bst.c, 16