直接上代码

package te.com;import java.util.LinkedList;import java.util.Queue;import java.util.logging.Level;class BinNode{    Integer val;    BinNode leftNode;    BinNode rightNode;    public BinNode(Integer val) {        this.val = val;    }    public BinNode() {    }    public Integer getVal() {        return val;    }    public void setVal(int val) {        this.val = val;    }    public BinNode getLeftNode() {        return leftNode;    }    public void setLeftNode(BinNode leftNode) {        this.leftNode = leftNode;    }    public BinNode getRightNode() {        return rightNode;    }    public void setRightNode(BinNode rightNode) {        this.rightNode = rightNode;    }    }public class binTree {    public static void main(String[] args) {        Integer[] a = {3,9,20,null,null,15,7,null,null,null,null};        int i=1;        BinNode root = new BinNode(a[0]);  // 根节点        BinNode current = null;        Integer value = null;                //层序创建二叉树        LinkedList
    
      queue = new LinkedList
     
      ();         queue.offer(root);        while(i
      
        queue = new LinkedList
       
        ();        BinNode current = null;        queue.offer(root);        while(!queue.isEmpty()) {            current = queue.poll();            if(current.getLeftNode()!=null) {                queue.offer(current.getLeftNode());                System.out.println("节点"+current.val+"的左孩子是"+current.getLeftNode().val);            }else {                System.out.println("节点"+current.val+"没有左孩子");            }            if(current.getRightNode()!=null) {                queue.offer(current.getRightNode());                System.out.println("节点"+current.val+"的右孩子是"+current.getRightNode().val);            }else {                System.out.println("节点"+current.val+"没有右孩子");            }        }        return 1;    }}
       
      
     
    

运行结果