diff --git a/TangDou/LanQiaoBei/ZhongGaoJi/LanQiao14STEMA202303/BC3.cpp b/TangDou/LanQiaoBei/ZhongGaoJi/LanQiao14STEMA202303/BC3.cpp
index 16d8ceb..e4e4835 100644
--- a/TangDou/LanQiaoBei/ZhongGaoJi/LanQiao14STEMA202303/BC3.cpp
+++ b/TangDou/LanQiaoBei/ZhongGaoJi/LanQiao14STEMA202303/BC3.cpp
@@ -14,9 +14,16 @@ int check(int x) {
         if ((res[i] - '0') % 2 == 0) return 0;
 
     // 判断转完的9进制是不是回文数
-    string str = res;
-    reverse(str.begin(), str.end());
-    return str == res;
+    // 方法1
+    // string str = res;
+    // reverse(str.begin(), str.end());
+    // return str == res;
+
+    // 方法2
+    for (int i = 0; i < (res.size() + 1) / 2; i++)
+        if (res[i] != res[res.size() - 1 - i]) return 0;
+
+    return 1;
 }
 int main() {
     int n, m;