数字0~9，拼成6位数，不能重复，都能拼成哪些组？

Answer 1

pascal:
type
number=0..9;
var
a,b,c,d,e,f:number;
begin
for a:=1 to 9 do
for b:=1 to 9 do
begin if a<>b then for c:=1 to 9 do
begin if (a<>c)and(c<>b) then for d:=1 to 9 do
begin if (a<>d)and(d<>b)and(d<>c) then for e:=1 to 9 do
begin if (e<>a)and(e<>b)and(e<>c)and(e<>d) then for f:=1 to 9 do
begin if (f<>a)and(f<>b)and(f<>c)and(f<>d)and(f<>e) then writeln(a,b,c,d,e,f,' ');end;end;end;end;end;
end.