diff --git a/15lanqiao/test8.cpp b/15lanqiao/test8.cpp
index 9bc54ca..f1e94ac 100644
--- a/15lanqiao/test8.cpp
+++ b/15lanqiao/test8.cpp
@@ -14,7 +14,7 @@ signed main(){
     }
     // 使用set数组去维护所有的区间和
     for(int i = 1; i<=n; i++){
-        for(int j = 1; j<=n; j++){
+        for(int j = i; j<=n; j++){
             ms.insert(s[j] - s[i-1]);
         }
     }