SortedArrayToBST.java

public class SortedArrayToBST {
    public BSTNode convert(int [] arrA, int start, int end){
		if(start>end){
			return null;
		}
		int mid = (start + end)/2;
		BSTNode root = new BSTNode(arrA[mid]);
		root.left = convert(arrA, start, mid-1);
		root.right =convert(arrA, mid+1, end);
		return root;
	}
	public void displayTree(BSTNode root){
		if(root!=null){
			displayTree(root.left);
			System.out.print(" " + root.data);
			displayTree(root.right);
		}
	}
	public static void main(String args[]){
		int [] arrA = {2,3,6,7,8,9,12,15,16,18,20};
		SortedArrayToBST s = new SortedArrayToBST();
		BSTNode x = s.convert(arrA, 0, arrA.length-1);
		System.out.println("Tree Display : ");
		s.displayTree(x);
	}
}
class BSTNode{
	int data;
	BSTNode left;
	BSTNode right;
	public BSTNode(int data){
		this.data = data;
		left = null;
		right = null;
	}
}