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 e20f147f..1c94994f 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
@@ -582,6 +582,61 @@ var maxDepth = function(root) {
 };
 ```
 
+## C
+二叉树最大深度递归
+```c
+int maxDepth(struct TreeNode* root){
+    //若传入结点为NULL，返回0
+    if(!root)
+        return 0;
+    
+    //求出左子树深度
+    int left = maxDepth(root->left);
+    //求出右子树深度
+    int right = maxDepth(root->right);
+    //求出左子树深度和右子树深度的较大值
+    int max = left > right ? left : right;
+    //返回较大值+1（1为当前层数）
+    return max + 1;
+}
+```
+二叉树最大深度迭代
+```c
+int maxDepth(struct TreeNode* root){
+    //若传入根节点为NULL，返回0
+    if(!root)
+        return 0;
+    
+    int depth = 0;
+    //开辟队列空间
+    struct TreeNode** queue = (struct TreeNode**)malloc(sizeof(struct TreeNode*) * 6000);
+    int queueFront = 0;
+    int queueEnd = 0;
+
+    //将根结点入队
+    queue[queueEnd++] = root;
+
+    int queueSize;
+    //求出当前队列中元素个数
+    while(queueSize = queueEnd - queueFront) {
+        int i;
+        //若当前队列中结点有左右子树，则将它们的左右子树入队
+        for(i = 0; i < queueSize; i++) {
+            struct TreeNode* tempNode = queue[queueFront + i];
+            if(tempNode->left)
+                queue[queueEnd++] = tempNode->left;
+            if(tempNode->right)
+                queue[queueEnd++] = tempNode->right;
+        }
+        //更新队头下标
+        queueFront += queueSize;
+        //深度+1
+        depth++;
+    }
+    return depth;
+}
+```
+
 -----------------------
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