BZOJ-3033 太鼓达人

#include <cstdio>
#include <algorithm>
#include <iostream>
#include <cctype>
#include <queue>
#include <cstring>
using namespace std;
#define rep(i, l, r) for(int i=l; i<=r; i++)
#define down(i, l, r) for(int i=l; i>=r; i--)
#define travel(x) for(edge *p=fir[x]; p; p=p->n)
#define maxn 12345
#define maxm 123456
#define inf 0x7fffffff
#define clr(x, c) memset(x, c, sizeof(x))
inline int read()
{
int x=0; char ch=getchar();
while (!isdigit(ch)) ch=getchar();
while (isdigit(ch)) { x=x*10+ch-'0'; ch=getchar(); }
return x;
}
int n=read(), m=1, top, s[maxn];
bool b[maxn];
bool dfs(int x)
{
s[++top]=x; b[x]=1;
if (top==m) return true;
if (!b[(x*2)%m] && dfs((x*2)%m)) return true;
if (!b[(x*2)%m+1] && dfs((x*2)%m+1))  return true;
--top; b[x]=0; return false;
}
int main()
{
rep(i, 1, n) m*=2; printf("%d ", m);
dfs(0);
m/=2; rep(i, 1, top) printf("%d", s[i]/m);
}