foo.cc: In function ‘int main()’:
foo.cc:9:23: warning: comparison of integer expressions of different signedness: ‘std::set<int>::size_type’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
    9 |     while (nums.size()<=n)
      |            ~~~~~~~~~~~^~~
foo.cc:16:24: warning: comparison of integer expressions of different signedness: ‘std::set<int>::size_type’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
   16 |         if (nums.size()>n)break;
      |             ~~~~~~~~~~~^~
foo.cc:18:24: warning: comparison of integer expressions of different signedness: ‘std::set<int>::size_type’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
   18 |         if (nums.size()>n)break;
      |             ~~~~~~~~~~~^~