java 二叉树最大深度 和 （前序、中序、后序）三种遍历实现

public class TreeNodeTest {
	
	TreeNodeTest left;
	TreeNodeTest right;
	int val;
	TreeNodeTest(int v){
		this.val = v;
	}
	
	public static void main(String[] args) {
		TreeNodeTest root = new TreeNodeTest(1);
		TreeNodeTest left = new TreeNodeTest(2);
		TreeNodeTest right = new TreeNodeTest(3);
		TreeNodeTest left1 = new TreeNodeTest(4);
		TreeNodeTest left2 = new TreeNodeTest(5);
		// 构建二叉树
		root.left = left;
		root.right = right;
		left.left = left1;
		left.right = left2;
		
		System.out.println("二叉树深度为："+getDeep(root));
		query(root);
	}
	// 遍历获取
	private static void query(TreeNodeTest root) {
		if(root == null){
			return;
		}
//		System.out.println(root.val); //前序遍历：先遍历根结点，然后遍历左子树，最后遍历右子树。
		query(root.left);
//		System.out.println(root.val);//	中序遍历:先遍历左子树，然后遍历根结点，最后遍历右子树。
		query(root.right);
		System.out.println(root.val);//	后序遍历:先遍历左子树，然后遍历右子树，最后遍历根节点。
	}
	// 获取深度
	private static int getDeep(TreeNodeTest root) {
		if(root == null){
			return 0;
		}
		int left = getDeep(root.left);
		int right = getDeep(root.right);
		return left>right?left+1:right+1;
	}
	
}public class TreeNodeTest {
	
	TreeNodeTest lef