比赛 |
NOIP_4 |
评测结果 |
AAAAAA |
题目名称 |
数列问题 |
最终得分 |
100 |
用户昵称 |
francis |
运行时间 |
0.000 s |
代码语言 |
Pascal |
内存使用 |
0.00 MiB |
提交时间 |
2008-09-19 20:26:14 |
显示代码纯文本
program dfs;
const
fin='dfs3.in';
fou='dfs3.out';
var
a:array[1..15]of longint;
b:array[1..30]of boolean;
num:array[1..15,1..15]of longint;
l:array[1..15]of longint;
deep,total,i,j,n:longint;
bo:boolean;
f1,f2:text;
procedure init;
begin
assign(f1,fin); assign(f2,fou);
reset(f1); rewrite(f2);
read(f1,n);
if n=0 then begin write(f2,0); close(f1); close(f2); halt; end;
if n=1 then
begin writeln(f2,1); writeln(f2,1); close(f1); close(f2); halt; end;
for i:=2 to (n+n-1) do
begin
bo:=true;
for j:=2 to trunc(sqrt(i)) do
if i mod j =0 then bo:=false;
if bo=true then b[i]:=true;
end;
for i:=2 to (n+n-1) do
for j:=1 to n do
if (i-j>0)and(b[i]=true)and(i-j<=n) then
begin
inc(l[j]); num[j,l[j]]:=i-j;
end;
for i:=1 to n do b[i]:=false;
end;
procedure dfs(deep:longint);
var
p,k,i,j:longint;
begin
k:=a[deep-1];
for i:=1 to l[k] do
begin
p:=num[k,i];
if b[p]=false then
begin
b[p]:=true;
a[deep]:=p;
if deep=n
then begin
inc(total);
for j:=1 to (n-1) do
write(f2,a[j],' '); writeln(f2,a[n]);
end
else dfs(deep+1);
b[p]:=false;
end;
end;
end;
begin
init;
for i:=1 to n do
begin
a[1]:=i;
b[i]:=true;
dfs(2);
b[i]:=false;
end;
write(f2,total);
close(f1); close(f2);
end.