diff --git a/problems/0110.平衡二叉树.md b/problems/0110.平衡二叉树.md
index 43a49758..e22a12b3 100644
--- a/problems/0110.平衡二叉树.md
+++ b/problems/0110.平衡二叉树.md
@@ -619,6 +619,36 @@ var isBalanced = function(root) {
 };
 ```
 
+##C
+递归法：
+```c
+int getDepth(struct TreeNode* node) {
+    //如果结点不存在，返回0
+    if(!node)
+        return 0;
+    //求出右子树深度
+    int rightDepth = getDepth(node->right);
+    //求出左子树深度
+    int leftDepth = getDepth(node->left);
+    //返回左右子树中的较大值+1
+    return rightDepth > leftDepth ? rightDepth + 1 : leftDepth + 1;
+}
+
+bool isBalanced(struct TreeNode* root) {
+    //递归结束条件为：传入结点为NULL，返回True
+    if(!root)
+        return 1;
+    //求出左右子树的深度
+    int leftDepth = getDepth(root->left);
+    int rightDepth = getDepth(root->right);
+    int diff;
+    //若左右子树绝对值差距大于1，返回False
+    if((diff = leftDepth - rightDepth) > 1 || diff < -1)
+        return 0;
+    //检查左右子树是否为平衡二叉树
+    return isBalanced(root->right) && isBalanced(root->left);
+}
+```
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)