diff --git a/TangDou/Topic/HDU3631.cpp b/TangDou/Topic/HDU3631.cpp
index 16ae0d4..c9ac698 100644
--- a/TangDou/Topic/HDU3631.cpp
+++ b/TangDou/Topic/HDU3631.cpp
@@ -14,10 +14,10 @@ void floyd(int k) {
 }
 int main() {
     while (cin >> n >> m >> q && n + m + q) {
-        if (t != 0) printf("\n"); // 谜之格式
+        if (t) printf("\n"); // 谜之格式
         printf("Case %d:\n", ++t);
-        memset(mp, inf, sizeof(mp));
-        memset(flag, false, sizeof(flag));
+        memset(mp, inf, sizeof mp);
+        memset(flag, false, sizeof flag);
         for (int i = 0; i <= n; ++i)
             mp[i][i] = 0;
         while (m--) {