/in/foo.c: In function 'main':
/in/foo.c:5:6: warning: variable 'd' set but not used [-Wunused-but-set-variable]
  int d=0;
      ^
/in/foo.c:9:5: warning: 'x' is used uninitialized in this function [-Wuninitialized]
  d=a*x*x+b*x+c;
    ~^~