diff --git a/problems/0116.填充每个节点的下一个右侧节点指针.md b/problems/0116.填充每个节点的下一个右侧节点指针.md
index 8b816f5e..34c666f3 100644
--- a/problems/0116.填充每个节点的下一个右侧节点指针.md
+++ b/problems/0116.填充每个节点的下一个右侧节点指针.md
@@ -133,14 +133,14 @@ public:
 // 递归法
 class Solution {
     public void traversal(Node cur) {
-        if(cur == null) return;
-        if(cur.left != null) cur.left.next = cur.right;
-        if(cur.right != null){
-            if(cur.next != null) cur.right.next = cur.next.left;
+        if (cur == null) return;
+        if (cur.left != null) cur.left.next = cur.right; // 操作1
+        if (cur.right != null) {
+            if(cur.next != null) cur.right.next = cur.next.left; //操作2
             else cur.right.next = null;
         }
-        traversal(cur.left);
-        traversal(cur.right);
+        traversal(cur.left);  // 左
+        traversal(cur.right); //右
     }
     public Node connect(Node root) {
         traversal(root);
@@ -152,26 +152,26 @@ class Solution {
 // 迭代法
 class Solution {
     public Node connect(Node root) {
-        if(root == null) return root;
+        if (root == null) return root;
         Queue<Node> que = new LinkedList<Node>();
         que.offer(root);
         Node nodePre = null;
         Node node = null;
-        while(!que.isEmpty()){
+        while (!que.isEmpty()) {
             int size = que.size();
-            for(int i=0; i<size; i++){ // 开始每一层的遍历
-                if(i == 0){
+            for (int i=0; i<size; i++) { // 开始每一层的遍历
+                if (i == 0) {
                     nodePre = que.peek(); // 记录一层的头结点
                     que.poll();
                     node = nodePre;
-                }else{
+                } else {
                     node = que.peek();
                     que.poll();
                     nodePre.next = node; // 本层前一个节点next指向本节点
                     nodePre = nodePre.next; 
                 }
-                if(node.left != null) que.offer(node.left);
-                if(node.right != null) que.offer(node.right);
+                if (node.left != null) que.offer(node.left);
+                if (node.right != null) que.offer(node.right);
             }
             nodePre.next = null; // 本层最后一个节点指向null
         }