【pascal】编写一个程序,生成1,2,3,4,5五个数字的全排列

Question

快

Answer 1

var
m,n:integer;
a:array[1..100]of integer;
fg:array[1..100]of boolean;

procedure print;
var
i:integer;
begin
for i:=1 to m do
write(a[i],' ');
writeln;
end;

procedure try(p:integer);
var
i:integer;
begin
if p>m then exit;
for i:=1 to n do
if not fg[i] then
begin
a[p]:=i;
fg[i]:=true;
if p=m then print
else try(p+1);
fg[i]:=false;
end;
end;

begin

fillchar(fg,sizeof(fg),0);
n:=5;
m:=5;
try(1);
end.
不行的话再来找我

Answer 2

{利用回溯法}
var t:array [1..5] of boolean;
a:array [1..5] of integer;
procedure px(i:integer);
var b:longint;
begin
if i>5 then {如果位数大于5，则输出}
begin
for b:=1 to 5 do
write(a[b]); {输出}
writeln;exit;
end;
for b:=1 to 5 do
if t[b]=true then {判断b数是否用过}
begin
t[b]:=false;a[i]:=b;
px(i+1);
t[b]:=true;a[i]:=0;
end;
end;
begin
fillchar(t,sizeof(t),true);
fillchar(a,sizeof(a),0);
px(1);
end.