/in/foo.cc: In function 'int main()':
/in/foo.cc:36:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j;
        ^
/in/foo.cc: In function 'void select(int*, int)':
/in/foo.cc:20:20: warning: 'index' may be used uninitialized in this function [-Wmaybe-uninitialized]
   int tmp = a[index];
                    ^