Tree_Traversal

import java.util.LinkedList;
import java.util.Queue;
class Tree {
                int value;
                Tree left;
                Tree right;

                Tree(int data) {
                this.value = data;
                }
                        static  void in_Order_Traversal(Tree node ) {
                               if(node!=null) {
                               print(node.left);
                               System.out.println(node.value);
                               print(node.right);
                }
            }

                        static void pre_Order_Traversal(Tree node) {
                               if(node!=null)  {
                               System.out.println(node.value);
                               preorder(node.left);
                               preorder(node.right);
                }
            }

                        static void post_Order_Traversal(Tree node) {
                               if(node!=null)  {
                               postorder(node.left);
                               postorder(node.right);
                               System.out.println(node.value);
            }

}
                        static void level_Order (Tree node) {
                               Queue<Tree> q1 = new LinkedList<Tree>();
                               q1.offer(node);
                                while(!q1.isEmpty()){
                                   Tree temp = q1.poll();
                                   System.out.println(temp.value);
                                   if(temp.left!=null){q1.offer(temp.left);}
                                   if(temp.right!=null){q1.offer(temp.right);}
                               }
                }
                        
                            public static void main(String args[]) {
                                    Tree t1 = new Tree(15);
                                    Tree t2 = new Tree(20);
                                    Tree t3 = new Tree(10);
                                    Tree t4 = new Tree(18);
                                    Tree t5 = new Tree(30);
                                    t2.left = t1;
                                    t2.right = t3;
                                    t1.right = t4;
                                    t3.right = t5; 
                                    level_Order_Traversal(t2);
                                    in_Order_Traversal(t2);
                                    pre_Order_Traversal(t2);
                                    post_Order_Traversal(t2);
                }
}