diff --git a/12lanqiao/test8-2.cpp b/12lanqiao/test8-2.cpp
new file mode 100644
index 0000000..f27fcd4
--- /dev/null
+++ b/12lanqiao/test8-2.cpp
@@ -0,0 +1,21 @@
+// lanqiao 1457 杨辉三角形(优化解法)
+#include<bits/stdc++.h>
+using namespace std;
+const int N = 1e5 + 10;
+int a[N], b[N];
+int main(){
+    int n; cin >>n;
+    if(n == 1){
+        cout << 1 << endl;
+        return 0;
+    } 
+    /*
+    如果某一行第二个数是n，那么第三个数一定是n(n-1)/2,算到44723行
+    44723*44723>10亿，所以算到前44723行即可
+    */
+   
+    return 0;
+}
+/* test samples -> 13
+6
+*/
\ No newline at end of file