foo.cc:2:1: error: expected unqualified-id before 'for'
 for(int i=1;i<=n;i++){
 ^~~
foo.cc:2:13: error: 'i' does not name a type
 for(int i=1;i<=n;i++){
             ^
foo.cc:2:18: error: 'i' does not name a type
 for(int i=1;i<=n;i++){
                  ^

正在同步测试数据，请稍后