在BST中查找一个数是否存在

/**
 * 判断二叉搜索树中的某个数是否存在
 * @author zhaizhg
 *
 */
public class FindOneInBST {
    
    

	public static void main(String[] args) {
    
    
		TreeNode root = new TreeNode(5);
		root.left = new TreeNode(2);
		root.right = new TreeNode(6);
		root.left.left = new TreeNode(1);
		root.right.right = new TreeNode(7);
		root.left.right = new TreeNode(4);
		root.left.right.left = new TreeNode(3);
		boolean flag = find(root, 3);
		System.out.println(flag);
	}
	
	static boolean find(TreeNode node, int num) {
    
    
		if (node == null) return false;
		if (node.val == num) return true;
		if (num < node.val) {
    
    
			return find(node.left, num);
		}
		return find(node.right, num);
	}

}