diff --git a/exercises/08_pointer/main.cpp b/exercises/08_pointer/main.cpp
index ba37173f5..f5acc3bd0 100644
--- a/exercises/08_pointer/main.cpp
+++ b/exercises/08_pointer/main.cpp
@@ -5,6 +5,14 @@ bool is_fibonacci(int *ptr, int len, int stride) {
     ASSERT(len >= 3, "`len` should be at least 3");
     // TODO: 编写代码判断从 ptr 开始，每 stride 个元素取 1 个元素，组成长度为 n 的数列是否满足
     // arr[i + 2] = arr[i] + arr[i + 1]
+    for(int i = 2; i < len; i++){
+        int cur   = *(ptr + i * stride);
+        int prev1 = *(ptr + (i-1) * stride);
+        int prev2 = *(ptr + (i-2) * stride);
+        if(cur != prev1 + prev2){
+            return false;
+        }
+    }
     return true;
 }