/in/foo.cc: In function 'int main()':
/in/foo.cc:158:11: warning: 'xmax' is used uninitialized in this function [-Wuninitialized]
  for(;xmin<=xmax;xmin++)
       ~~~~^~~~~~
/in/foo.cc:158:2: warning: 'xmin' may be used uninitialized in this function [-Wmaybe-uninitialized]
  for(;xmin<=xmax;xmin++)
  ^~~