用2-8可以组成多少个没有重复数字,且能被11整除的七位数?

432个.
请看FreePascal程序：
var
n,i,j,t,p:longint;
a:array[1..10] of longint;
b:array[1..10] of boolean;
procedure try(x:longint);
var
i:longint;
begin
if (x=n) and (p mod 11=0) then inc(t);
for i:=1 to n do
if not b[i] then
begin
b[i]:=true;
p:=p*10+a[i];
try(x+1);
p:=p div 10;
b[i]:=false;
end;
end;
begin
readln(n);
t:=0; p:=0;
for i:=1 to n do
begin
read(a[i]);
b[i]:=false;
end;
try(0);
writeln(t);
end.
你可以找懂编程的看看.