/in/foo.cc: In function 'int main()':
/in/foo.cc:34:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         for(int i=0;i<words.size();i++){
      |                     ~^~~~~~~~~~~~~
/in/foo.cc:35:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |                 for(int j=i+1;j<words.size();j++){
      |                               ~^~~~~~~~~~~~~
/in/foo.cc:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for(int k=1;k<yue.size();k++){
      |                     ~^~~~~~~~~~~