diff --git a/problems/0104.二叉树的最大深度.md b/problems/0104.二叉树的最大深度.md
index ab3ce52e..b89dbf45 100644
--- a/problems/0104.二叉树的最大深度.md
+++ b/problems/0104.二叉树的最大深度.md
@@ -738,26 +738,36 @@ function maxDepth(root: TreeNode | null): number {
 
 ```typescript
 // 后续遍历（自下而上）
-function maxDepth(root: TreeNode | null): number {
-    if (root === null) return 0;
-    return Math.max(maxDepth(root.left), maxDepth(root.right)) + 1;
-};
+function maxDepth(root: Node | null): number {
+    if (root === null) return 0
+    let depth = 0
+    for (let i = 0; i < root.children.length; i++) {
+        depth = Math.max(depth, maxDepth(root.children[i]))
+    }
+    return depth + 1
+}
 
 // 前序遍历(自上而下)
-function maxDepth(root: TreeNode | null): number {
-    function recur(node: TreeNode | null, count: number) {
-        if (node === null) {
-            resMax = resMax > count ? resMax : count;
-            return;
+function maxDepth(root: Node | null): number {
+    if (root === null) return 0
+
+    let depth: number = 0
+    const queue: Array<Node | null> = []
+    queue.push(root)
+
+    while (queue.length > 0) {
+        let len = queue.length
+        depth++
+        for (let i = 0; i < len; i++) {
+            // 当前层遍历
+            let curNode: Node | null = queue.shift()!
+                for (let j = 0; j < curNode.children.length; j++) {
+                    if (curNode.children[j]) queue.push(curNode.children[j])
+                }
         }
-        recur(node.left, count + 1);
-        recur(node.right, count + 1);
     }
-    let resMax: number = 0;
-    let count: number = 0;
-    recur(root, count);
-    return resMax;
-};
+    return depth
+}
 
 
 ```