/in/foo.cc: In function 'void mergesort(int, int)':
/in/foo.cc:95:9: warning: variable 'i' set but not used [-Wunused-but-set-variable]
     int i,j,m,k;
         ^
/in/foo.cc:95:11: warning: variable 'j' set but not used [-Wunused-but-set-variable]
     int i,j,m,k;
           ^
/in/foo.cc:95:15: warning: unused variable 'k' [-Wunused-variable]
     int i,j,m,k;
               ^