Added Tree-App

01. DataStructures/TreeApp.java

@@ -0,0 +1,342 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package Projects;
+
+/**
+ *
+ * @author AsadUllah
+ */
+import java.io.*;
+import java.util.*;
+import java.lang.Integer; 
+class Node
+{
+public int iData;
+public double dData;
+public Node leftChild;
+public Node rightChild;
+public void displayNode()
+{
+System.out.print('{');
+System.out.print(iData);
+System.out.print(", ");
+System.out.print(dData);
+System.out.print("} ");
+}
+}	// end class Node
+class Tree
+{
+private Node root; 
+public Tree() 
+{ 
+root = null; 
+} 
+public Node find(int key)
+{ 
+Node current = root; 
+while(current.iData != key) 
+{
+if(key < current.iData)
+current = current.leftChild;
+else 
+current = current.rightChild;
+if(current == null) 
+return null; 
+}
+return current;
+} 
+
+public void insert(int id, double dd)
+{
+Node newNode = new Node(); 
+newNode.iData = id; 
+newNode.dData = dd;
+if(root==null) 
+root = newNode;
+else 
+{
+Node current = root; 
+Node parent;
+while(true) 
+{
+parent = current;
+if(id < current.iData) 
+{
+current = current.leftChild;
+if(current == null) 
+{ 
+parent.leftChild = newNode;
+return;
+}
+} 
+else // or go right?
+{
+current = current.rightChild;
+if(current == null)
+{ 
+parent.rightChild = newNode;
+return;
+}
+} 
+} 
+} 
+} 
+public boolean delete(int key) 
+{ 
+Node current = root;
+Node parent = root;
+boolean isLeftChild = true;
+while(current.iData != key) 
+{
+parent = current;
+if(key < current.iData) 
+{
+isLeftChild = true;
+current = current.leftChild;
+}
+else 
+{
+isLeftChild = false;
+current = current.rightChild;
+}
+if(current == null) 
+return false;
+} 
+if(current.leftChild==null && current.rightChild==null)
+{
+if(current == root) 
+root = null; 
+else if(isLeftChild)
+parent.leftChild = null; 
+else 
+parent.rightChild = null;
+}
+
+else if(current.rightChild==null)
+if(current == root)
+root = current.leftChild;
+else if(isLeftChild)
+parent.leftChild = current.leftChild;
+else
+parent.rightChild = current.leftChild;
+else if(current.leftChild==null)
+ if(current == root)
+root = current.rightChild;
+ else if(isLeftChild)
+parent.leftChild = current.rightChild;
+ else
+parent.rightChild = current.rightChild;
+else 
+{
+Node successor = getSuccessor(current);
+if(current == root)
+root = successor;
+else if(isLeftChild)
+parent.leftChild = successor;
+else
+parent.rightChild = successor;
+	successor.leftChild = current.leftChild;
+} 
+
+return true;
+} 
+
+private Node getSuccessor(Node delNode)
+{
+Node successorParent = delNode;
+Node successor = delNode;
+Node current = delNode.rightChild; 
+while(current != null) 
+{ 
+successorParent = successor;
+successor = current;
+current = current.leftChild; 
+}
+
+if(successor != delNode.rightChild) 
+{ 
+successorParent.leftChild = successor.rightChild;
+successor.rightChild = delNode.rightChild;
+}
+return successor;
+ }
+
+public void traverse(int traverseType)
+{
+switch(traverseType)
+{
+case 1: System.out.print("\nPreorder traversal: ");
+preOrder(root);
+break;
+case 2: System.out.print("\nInorder traversal: ");
+inOrder(root);
+break;
+case 3: System.out.print("\nPostorder traversal: ");
+postOrder(root);
+break;
+}
+System.out.println();
+}
+private void preOrder(Node localRoot)
+{
+if(localRoot != null)
+{
+localRoot.displayNode();
+preOrder(localRoot.leftChild);
+preOrder(localRoot.rightChild);
+}
+}
+private void inOrder(Node localRoot)
+{
+if(localRoot != null)
+{
+inOrder(localRoot.leftChild);
+localRoot.displayNode();
+inOrder(localRoot.rightChild);
+}
+}
+private void postOrder(Node localRoot)
+{
+if(localRoot != null)
+{
+postOrder(localRoot.leftChild);
+postOrder(localRoot.rightChild);
+localRoot.displayNode();
+}
+}
+public void displayTree()
+{
+Stack globalStack = new Stack();
+globalStack.push(root);
+int nBlanks = 32;
+boolean isRowEmpty = false;
+System.out.println(
+".............................................");
+while(isRowEmpty==false)
+{
+Stack localStack = new Stack();
+isRowEmpty = true;
+for(int j=0; j<nBlanks; j++)
+System.out.print(" ");
+while(globalStack.isEmpty()==false)
+{
+Node temp = (Node)globalStack.pop();
+if(temp != null)
+{
+System.out.print(temp.iData);
+localStack.push(temp.leftChild);
+localStack.push(temp.rightChild);
+if(temp.leftChild != null || temp.rightChild != null)
+isRowEmpty = false;
+}
+else
+{
+System.out.print("--");
+localStack.push(null);
+localStack.push(null);
+}
+for( int j = 0 ; j < ( ( nBlanks * 2 ) - 2 ) ; j++ )
+ System.out.print(" ");
+}
+System.out.println();
+nBlanks /= 2;
+while(localStack.isEmpty()==false)
+globalStack.push( localStack.pop() );
+} 
+System.out.println(".........................................");
+} 
+} // end of class Tree 
+
+class TreeApp
+{
+public static void main(String[] args) throws IOException
+{
+int value;
+Tree theTree = new Tree();
+theTree.insert(50, 1.5);
+theTree.insert(25, 1.2);
+theTree.insert(75, 1.7);
+theTree.insert(12, 1.5);
+theTree.insert(37, 1.2);
+theTree.insert(43, 1.7);
+theTree.insert(30, 1.5);
+theTree.insert(33, 1.2);
+theTree.insert(87, 1.7);
+theTree.insert(93, 1.5);
+theTree.insert(97, 1.5);
+while(true)
+{
+putText("Enter first letter of ");
+putText("show, insert, find, delete, or traverse: ");
+int choice = getChar();
+switch(choice)
+{
+case 's':
+theTree.displayTree();
+break;
+case 'i':
+putText("Enter value to insert: ");
+value = getInt();
+theTree.insert(value, value + 0.9);
+break;
+case 'f':
+putText("Enter value to find: ");
+value = getInt();
+Node found = theTree.find(value);
+if(found != null)
+{
+putText("Found: ");
+found.displayNode();
+putText("\n");
+}
+else
+putText("Could not find " + value + '\n');
+break;
+case 'd':
+putText("Enter value to delete: ");
+value = getInt();
+boolean didDelete = theTree.delete(value);
+if(didDelete)
+putText("Deleted " + value + '\n');
+else
+putText("Could not delete " + value + '\n');
+break;
+case 't':
+putText("Enter type 1, 2 or 3: ");
+value = getInt();
+theTree.traverse(value);
+break;
+default:
+putText("Invalid entry\n");
+} 
+}
+}
+
+public static void putText(String s)
+{
+System.out.print(s);
+System.out.flush();
+}
+public static String getString() throws IOException
+{
+InputStreamReader isr = new InputStreamReader(System.in);
+BufferedReader br = new BufferedReader(isr);
+String s = br.readLine();
+return s;
+}
+public static char getChar() throws IOException
+{
+String s = getString();
+return s.charAt(0);
+}
+public static int getInt() throws IOException
+{
+String s = getString();
+return Integer.parseInt(s);
+}
+
+} // end class TreeApp
+