diff --git a/problems/0112.路径总和.md b/problems/0112.路径总和.md
index 7aa5f2a1..b1f01336 100644
--- a/problems/0112.路径总和.md
+++ b/problems/0112.路径总和.md
@@ -155,14 +155,14 @@ public:
 以上代码精简之后如下：
 
 ```cpp
-class solution {
+class Solution {
 public:
     bool hasPathSum(TreeNode* root, int sum) {
-        if (root == null) return false;
+        if (!root) return false;
         if (!root->left && !root->right && sum == root->val) {
             return true;
         }
-        return haspathsum(root->left, sum - root->val) || haspathsum(root->right, sum - root->val);
+        return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val);
     }
 };
 ```