foo.cc: In function ‘int main()’:
foo.cc:18:18: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘__gnu_cxx::__alloc_traits<std::allocator<long long int>, long long int>::value_type’ {aka ‘long long int’} [-Wformat=]
   18 |         printf("%d\n",v[x]);
      |                 ~^
      |                  |
      |                  int
      |                 %lld