/in/foo.cc: In function 'int main()':
/in/foo.cc:8:11: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'class std::vector<int>' with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
    8 |     memset(vv,0,sizeof(vv));
      |     ~~~~~~^~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/12/vector:64,
                 from /usr/include/c++/12/queue:61,
                 from /usr/include/x86_64-linux-gnu/c++/12/bits/stdc++.h:86,
                 from /in/foo.cc:1:
/usr/include/c++/12/bits/stl_vector.h:423:11: note: 'class std::vector<int>' declared here
  423 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/in/foo.cc:9:11: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'class std::vector<int>' with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
    9 |     memset(pp,0,sizeof(pp));
      |     ~~~~~~^~~~~~~~~~~~~~~~~
/usr/include/c++/12/bits/stl_vector.h:423:11: note: 'class std::vector<int>' declared here
  423 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/in/foo.cc:54:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |             for(int k=0;k<vv[i].size();k++){
      |                         ~^~~~~~~~~~~~~