diff --git a/OJ notes/pages/Leetcode Product-of-Array-Except-Self.md b/OJ notes/pages/Leetcode Product-of-Array-Except-Self.md
index 99e8823..b8badf6 100644
--- a/OJ notes/pages/Leetcode Product-of-Array-Except-Self.md	
+++ b/OJ notes/pages/Leetcode Product-of-Array-Except-Self.md	
@@ -96,6 +96,30 @@ loop.
 
 Third version:
 
+```cpp
+class Solution {
+public:
+  vector<int> productExceptSelf(vector<int> &nums) {
+    // Optimized one-pass prefix sum & suffix sum
+    int size = nums.size();
+
+    vector<int> ans(size, 1);
+
+    int prefix = 1, suffix = 1;
+
+    for (int i = 0; i < size; i++) {
+      ans[i] *= prefix;
+      prefix *= nums[i];
+
+      ans[size - i - 1] *= suffix;
+      suffix *= nums[size - i - 1];
+    }
+
+    return ans;
+  }
+};
+```
+
 Second version:
 
 ```cpp