BinarySearchTree in JAVA Added :)

Data Structures/Binary Search Tree/JAVA/BinarySearchTree.java

@@ -0,0 +1,161 @@
+//binary search tree by Jasani Dhruv
+public class BinarySearchTree {
+	public static  Node root;
+	public BinarySearchTree(){
+		this.root = null;
+	}
+
+	public boolean find(int id){
+		Node current = root;
+		while(current!=null){
+			if(current.data==id){
+				return true;
+			}else if(current.data>id){
+				current = current.left;
+			}else{
+				current = current.right;
+			}
+		}
+		return false;
+	}
+	public boolean delete(int id){
+		Node parent = root;
+		Node current = root;
+		boolean isLeftChild = false;
+		while(current.data!=id){
+			parent = current;
+			if(current.data>id){
+				isLeftChild = true;
+				current = current.left;
+			}else{
+				isLeftChild = false;
+				current = current.right;
+			}
+			if(current ==null){
+				return false;
+			}
+		}
+		//if i am here that means we have found the node
+		//Case 1: if node to be deleted has no children
+		if(current.left==null && current.right==null){
+			if(current==root){
+				root = null;
+			}
+			if(isLeftChild ==true){
+				parent.left = null;
+			}else{
+				parent.right = null;
+			}
+		}
+		//Case 2 : if node to be deleted has only one child
+		else if(current.right==null){
+			if(current==root){
+				root = current.left;
+			}else if(isLeftChild){
+				parent.left = current.left;
+			}else{
+				parent.right = current.left;
+			}
+		}
+		else if(current.left==null){
+			if(current==root){
+				root = current.right;
+			}else if(isLeftChild){
+				parent.left = current.right;
+			}else{
+				parent.right = current.right;
+			}
+		}else if(current.left!=null && current.right!=null){
+
+			//now we have found the minimum element in the right sub tree
+			Node successor	 = getSuccessor(current);
+			if(current==root){
+				root = successor;
+			}else if(isLeftChild){
+				parent.left = successor;
+			}else{
+				parent.right = successor;
+			}			
+			successor.left = current.left;
+		}		
+		return true;		
+	}
+
+	public Node getSuccessor(Node deleleNode){
+		Node successsor =null;
+		Node successsorParent =null;
+		Node current = deleleNode.right;
+		while(current!=null){
+			successsorParent = successsor;
+			successsor = current;
+			current = current.left;
+		}
+		//check if successor has the right child, it cannot have left child for sure
+		// if it does have the right child, add it to the left of successorParent.
+//		successsorParent
+		if(successsor!=deleleNode.right){
+			successsorParent.left = successsor.right;
+			successsor.right = deleleNode.right;
+		}
+		return successsor;
+	}
+	public void insert(int id){
+		Node newNode = new Node(id);
+		if(root==null){
+			root = newNode;
+			return;
+		}
+		Node current = root;
+		Node parent = null;
+		while(true){
+			parent = current;
+			if(id<current.data){				
+				current = current.left;
+				if(current==null){
+					parent.left = newNode;
+					return;
+				}
+			}else{
+				current = current.right;
+				if(current==null){
+					parent.right = newNode;
+					return;
+				}
+			}
+		}
+	}
+	public void display(Node root){
+		if(root!=null){
+			display(root.left);
+			System.out.print(" " + root.data);
+			display(root.right);
+		}
+	}
+	public static void main(String arg[]){
+		BinarySearchTree b = new BinarySearchTree();
+		b.insert(3);b.insert(8);
+		b.insert(1);b.insert(4);b.insert(6);b.insert(2);b.insert(10);b.insert(9);
+		b.insert(20);b.insert(25);b.insert(15);b.insert(16);
+		System.out.println("Original Tree : ");
+		b.display(b.root);		
+		System.out.println("");
+		System.out.println("Check whether Node with value 4 exists : " + b.find(4));
+		System.out.println("Delete Node with no children (2) : " + b.delete(2));		
+		b.display(root);
+		System.out.println("\n Delete Node with one child (4) : " + b.delete(4));		
+		b.display(root);
+		System.out.println("\n Delete Node with Two children (10) : " + b.delete(10));		
+		b.display(root);
+	}
+}
+
+class Node{
+	int data;
+	Node left;
+	Node right;	
+	public Node(int data){
+		this.data = data;
+		left = null;
+		right = null;
+	}
+}