/in/foo.c: In function 'main':
/in/foo.c:5:20: error: array type has incomplete element type 'int[]'
  int xmin,xmax,i,j,a[2][],num=0;
                    ^
/in/foo.c:5:20: note: declaration of 'a' as multidimensional array must have bounds for all dimensions except the first
/in/foo.c:11:3: error: expected ';' before 'printf'
   printf("\n");
   ^~~~~~
/in/foo.c:5:20: warning: unused variable 'a' [-Wunused-variable]
  int xmin,xmax,i,j,a[2][],num=0;
                    ^
/in/foo.c: In function 'find':
/in/foo.c:16:10: warning: variable 'x' set but not used [-Wunused-but-set-variable]
  int i,j,x,num=0;
          ^
/in/foo.c:16:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,x,num=0;
        ^