JZYZOJ1384 种花小游戏 状压dp

http://172.20.6.3/Problem_Show.asp?id=1384

 最开始以为是dfs然后超时了，然后调了半天调成dp，还不如再写一遍。。。

代码

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<cmath>
 using namespace std;
 const int maxn=<<;
 int n,x,y;
 int a[][]={};
 double f[(<<)+][]={};
 int vis[]={};
 double ans=(<<);
 int main(){
     scanf("%d",&n);int x,y;
     for(int i=;i<n;i++){
         scanf("%d%d",&a[i][],&a[i][]);
     }scanf("%d%d",&x,&y);
     int ma=<<n;
     for(int i=;i<ma;i++){
         for(int j=;j<n;j++){
             f[i][j]=1.0*maxn;
         }
     }
     int x1,x2;double y1,y2,wtf;
     for(int i=;i<n;i++){
         x1=<<i;
         y1=(double)abs(a[i][]-x);y2=(double)abs(a[i][]-y);
         wtf=sqrt((double)y1*y1+y2*y2);
         f[x1][i]=wtf;
     }int wt=;
     for(int i=;i<ma;i++){
         if(i==wt){wt*=;continue;}
         for(int j=;j<n;j++){
             x1=<<j;if((x1|i)!=i)continue;
             for(int w=;w<n;w++){
                 x2=<<w;
                 if((x2|i)!=i||w==j)continue;
                 y1=(double)abs(a[j][]-a[w][]);y2=(double)abs(a[j][]-a[w][]);
                 wtf=sqrt((double)y1*y1+y2*y2);
                 if(f[i-x1][w]+wtf-f[i][j]<){
                     f[i][j]=f[i-x1][w]+wtf;
                 }
             }
         }
     }double ans=maxn;
     for(int i=;i<n;i++){
         if(f[ma-][i]<ans)ans=f[ma-][i];
     }
     printf("%.2f",ans);
     return ;
 }