/in/foo.cc: In function 'int main()':
/in/foo.cc:6:19: warning: unused variable 'b' [-Wunused-variable]
  int n,a[10000],i,b[10000],j=0;
                   ^
/in/foo.cc:6:28: warning: unused variable 'j' [-Wunused-variable]
  int n,a[10000],i,b[10000],j=0;
                            ^