/in/foo.cc: In function 'void seive(int)':
/in/foo.cc:11:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |                 for(int j=0;j<Primes.size()&&i*Primes[j]<=n;j++)
      |                             ~^~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:22:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for(int i=0;i<Primes.size();i++)
      |                     ~^~~~~~~~~~~~~~