Java 层序创建和遍历二叉树

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

转载于:https://www.cnblogs.com/lick468/p/10667869.html