foo.cc: In function 'std::string ss(std::string)':
foo.cc:6:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    6 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:20:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |  for(int i=0;i<s.size()-1;i++)
      |              ~^~~~~~~~~~~
foo.cc:22:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |   while(s[i]==' '&&i<s.size()||s[i+1]==' '&&i<s.size()) i++;
      |                    ~^~~~~~~~~
foo.cc:22:46: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |   while(s[i]==' '&&i<s.size()||s[i+1]==' '&&i<s.size()) i++;
      |                                             ~^~~~~~~~~
foo.cc:22:18: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   22 |   while(s[i]==' '&&i<s.size()||s[i+1]==' '&&i<s.size()) i++;

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