Tree data structure 

class Node
{
public int iData; // data item (used as key value)
public double dData; //other data
public Node leftChild; // this node’s left child
public Node rightChild; //this node’s right child

public void displayNode( ){
System.out.print(“{“);
System.out.print(iData);
System.out.print(”, “);
System.out.print(dData);
System.out.print( “ } ”);
}
}
 
//Tree class find method
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;
}
//Trees insert method
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; //start at root
Node parent = root;
while(true){
parent = current;

if(id<current.iData){
current = current.leftChild;
if(current == null){
parent.leftChild = newNode;
return;
}
}
else{
current = current.rightChild;
if(current == null){
parent.rightChild = newNode;
return;
}
}
}
}
}
//tree class INORDER traversing method
private void inOrder(Node localroot){
if(localroot != null){
inOrder(localroot.leftChild);
localroot.displayNode();
inOrder(localroot.rightChild);
}
}
//tree class PREORDER traversing method
private void preOrder(Node localroot){
if(localroot != null){
localroot.displayNode();
preOrder(localroot.leftChild);
preOrder(localroot.rightChild);
}
}
//tree class POSTORDER traversing method
private void postOrder(Node localroot){
if(localroot != null){
localroot.displayNode();
preOrder(localroot.leftChild);
preOrder(localroot.rightChild);
}
}