/in/foo.c: In function 'main':
/in/foo.c:18:14: error: 'a' undeclared (first use in this function)
  scanf("%d",&a[i];);
              ^
/in/foo.c:18:14: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:18:18: error: expected ')' before ';' token
  scanf("%d",&a[i];);
                  ^