foo.cc: In function 'void Test1()':
foo.cc:11:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |  for(i=0;i<s.length();i++){
      |          ~^~~~~~~~~~~
foo.cc:17:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |  for(j=i+1;j<s.length();j++){
      |            ~^~~~~~~~~~~
foo.cc:26:6: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |  if(k==s2.length())
      |     ~^~~~~~~~~~~~~
foo.cc:28:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  else if(k>s2.length()){
      |          ~^~~~~~~~~~~~
foo.cc:8:9: warning: unused variable 'a' [-Wunused-variable]
    8 |  double a;
      |         ^

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