/in/foo.cc: In function 'int min1()':
/in/foo.cc:17:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(;i<vi.size()-1;i++){
       ~^~~~~~~~~~~~
/in/foo.cc: In function 'int ou()':
/in/foo.cc:36:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(i<vi.size()-1&&j>0){
         ~^~~~~~~~~~~~
/in/foo.cc: In function 'int ji()':
/in/foo.cc:78:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=vi.size()-1;i>=vi.size()-vi.size()/2;i--){
                        ~^~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:81:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<vi.size()/2+1;i++){
              ~^~~~~~~~~~~~~~