foo.cc: In function ‘void build()’:
foo.cc:63:30: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   63 |                 for(int i=0;i<temp.size()-1;++i)
      |                             ~^~~~~~~~~~~~~~
foo.cc:64:40: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   64 |                         for(int j=i+1;j<temp.size();++j)
      |                                       ~^~~~~~~~~~~~
foo.cc:68:45: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses]
   68 |                                 int wt=(x&y)+(x^y)<<1;
      |                                        ~~~~~^~~~~~
foo.cc:86:38: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   86 |                         for(int i=0;i<temp.size();++i)
      |                                     ~^~~~~~~~~~~~
foo.cc:90:48: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   90 |                                 int r=temp[(i+1>temp.size()-1?0:i+1)]-'0';
      |                                             ~~~^~~~~~~~~~~~~~
foo.cc:111:30: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
  111 |                 for(int i=0;i<=temp.size();++i)
      |                             ~^~~~~~~~~~~~~
foo.cc:114:38: warning: comparison of integer expressions of different signedness: ‘long long int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
  114 |                         int r=temp[(i>temp.size()-1?0:i)]-'0';
      |                                     ~^~~~~~~~~~~~~~
foo.cc:120:73: warning: comparison of integer expressions of different signedness: ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} and ‘long long int’ [-Wsign-compare]
  120 |                                 if(new_string.empty()||new_string.size()>max_len)//||new_string.size()!=temp.size()+1)
      |                                                        ~~~~~~~~~~~~~~~~~^~~~~~~~