feat: 二叉树按层遍历

Author: dairongpeng

07-二叉树基本算法.md

@@ -272,60 +272,56 @@ func main() {
 
 > 按层打印输出二叉树
 
-```Java
-package class07;
-
-import java.util.LinkedList;
-import java.util.Queue;
+```GO
+package main
 
-public class Code03_LevelTraversalBT {
+import "fmt"
 
-	public static class Node {
-		public int value;
-		public Node left;
-		public Node right;
+type Node struct {
+	// 二叉树节点上的值
+	Val int
+	// 左孩子
+	Left *Node
+	// 右孩子
+	Right *Node
+}
 
-		public Node(int v) {
-			value = v;
-		}
+// Level 按层遍历二叉树
+func (head *Node) Level() {
+	if head == nil {
+		return
 	}
-
-	public static void level(Node head) {
-		if (head == null) {
-			return;
+	hd := head
+	// 简单实现一个队列
+	queue := make([]*Node, 0)
+	// 加入头结点
+	queue = append(queue, hd)
+	// 队列不为空出队打印，把当前节点的左右孩子加入队列
+	for len(queue) != 0 {
+		// 弹出队列头部的元素
+		cur := queue[0]
+		queue = queue[1:]
+		fmt.Println(cur.Val)
+		if cur.Left != nil {
+			queue = append(queue, cur.Left)
 		}
-		// 准备一个辅助队列
-		Queue<Node> queue = new LinkedList<>();
-		// 加入头结点
-		queue.add(head);
-		// 队列不为空出队打印，把当前节点的左右孩子加入队列
-		while (!queue.isEmpty()) {
-			Node cur = queue.poll();
-			System.out.println(cur.value);
-			if (cur.left != null) {
-				queue.add(cur.left);
-			}
-			if (cur.right != null) {
-				queue.add(cur.right);
-			}
+		if cur.Right != nil {
+			queue = append(queue, cur.Right)
 		}
 	}
+}
 
-	public static void main(String[] args) {
-		Node head = new Node(1);
-		head.left = new Node(2);
-		head.right = new Node(3);
-		head.left.left = new Node(4);
-		head.left.right = new Node(5);
-		head.right.left = new Node(6);
-		head.right.right = new Node(7);
-
-		level(head);
-		System.out.println("========");
-	}
+func main() {
+	head := &Node{Val: 1}
+	head.Left = &Node{Val: 2}
+	head.Right = &Node{Val: 3}
+	head.Left.Left = &Node{Val: 4}
+	head.Left.Right = &Node{Val: 5}
+	head.Right.Left = &Node{Val: 6}
+	head.Right.Right = &Node{Val: 7}
 
+	head.Level()
 }
-
 ```
 
 > 找到二叉树的最大宽度