refactor: 0102.二叉树的层序遍历.md

problems/0102.二叉树的层序遍历.md

@@ -1297,26 +1297,26 @@ func averageOfLevels(root *TreeNode) []float64 {
 
 ```javascript
 var averageOfLevels = function(root) {
-    //层级平均值
-    let res = [], queue = [];
-    queue.push(root);
-
-    while(queue.length && root!==null) {
-        //每一层节点个数
-        let length = queue.length;
-        //sum记录每一层的和
-        let sum = 0;
-        for(let i=0; i < length; i++) {
-            let node = queue.shift();
-            sum += node.val;
-            node.left && queue.push(node.left);
-            node.right && queue.push(node.right);
-        }
-        //每一层的平均值存入数组res
-        res.push(sum/length);
+  let res = [],
+    queue = [];
+  queue.push(root);
+  while (queue.length) {
+    // 每一层节点个数;
+    let lengthLevel = queue.length,
+      len = queue.length,
+      //   sum记录每一层的和;
+      sum = 0;
+    while (lengthLevel--) {
+      const node = queue.shift();
+      sum += node.val;
+      //   队列存放下一层节点
+      node.left && queue.push(node.left);
+      node.right && queue.push(node.right);
     }
-
-    return res;
+    // 求平均值
+    res.push(sum / len);
+  }
+  return res;
 };
 ```
 
@@ -1927,26 +1927,28 @@ func max(x, y int) int {
 #### Javascript：
 
 ```javascript
-var largestValues = function(root) {
-    //使用层序遍历
-    let res = [], queue = [];
-    queue.push(root);
-
-    while(root !== null && queue.length) {
-        //设置max初始值就是队列的第一个元素
-        let max = queue[0].val;
-        let length = queue.length;
-        while(length--) {
-            let node = queue.shift();
-            max = max > node.val ? max : node.val;
-            node.left && queue.push(node.left);
-            node.right && queue.push(node.right);
-        }
-        //把每一层的最大值放到res数组
-        res.push(max);
-    }
-
+var largestValues = function (root) {
+  let res = [],
+    queue = [];
+  queue.push(root);
+  if (root === null) {
     return res;
+  }
+  while (queue.length) {
+    let lengthLevel = queue.length,
+      // 初始值设为负无穷大
+      max = -Infinity;
+    while (lengthLevel--) {
+      const node = queue.shift();
+      //   在当前层中找到最大值
+      max = Math.max(max, node.val);
+      // 找到下一层的节点
+      node.left && queue.push(node.left);
+      node.right && queue.push(node.right);
+    }
+    res.push(max);
+  }
+  return res;
 };
 ```