/in/foo.cc: In function 'int main()':
/in/foo.cc:21:14: warning: unused variable 't' [-Wunused-variable]
  int n,t1,t2,t,t0,n0,nx,x1=0,x2=0;
              ^
/in/foo.cc:21:22: warning: variable 'nx' set but not used [-Wunused-but-set-variable]
  int n,t1,t2,t,t0,n0,nx,x1=0,x2=0;
                      ^~