1 Source Code
 2 Problem: 3537        User: sdfzyhy
 3 Memory: 692K        Time: 141MS
 4 Language: G++        Result: Accepted
 5 
 6     Source Code
 7 
 8     //POJ 3537
 9     #include<cmath>
10     #include<queue>
11     #include<vector>
12     #include<string>
13     #include<cstdio>
14     #include<cstring>
15     #include<cstdlib>
16     #include<iostream>
17     #include<algorithm>
18     #define rep(i,n) for(int i=0;i<n;++i)
19     #define F(i,j,n) for(int i=j;i<=n;++i)
20     #define D(i,j,n) for(int i=j;i>=n;--i)
21     using namespace std;
22 
23     int getint(){
24         int r=0,c=1; char ch=getchar();
25         for(;!isdigit(ch);ch=getchar()) if (ch==‘-‘) c=-1;
26         for(;isdigit(ch);ch=getchar()) r=r*10+ch-‘0‘;
27         return r*c;
28     }
29     const int N=2010,INF=~0u>>2;
30     const double eps=1e-9;
31     /******************template***********************/
32     int dp[N],n;
33     bool vis[N],mark[N];
34 
35     int main(){
36         n=getint();
37         dp[0]=0; dp[1]=dp[2]=dp[3]=1;
38         F(i,4,n){
39             memset(mark,0,sizeof mark);
40             mark[dp[i-3]]=mark[dp[i-4]]=mark[dp[i-5]]=1;
41             for(int j=1;j<=i-5-j;j++)
42                 mark[dp[j]^dp[i-5-j]]=1;
43             F(j,0,n) if(!mark[j]){ dp[i]=j; break;}
44         }
45         printf("%d\n",dp[n] ? 1 : 2);
46         return 0;
47     }