foo.cc: In function ‘int main()’:
foo.cc:19:38: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   19 |                         for(int i=0;i<a.size();i++)
      |                                     ~^~~~~~~~~

正在同步测试数据，请稍后