hdu 1572(dfs+最短路）

1 #include<iostream>
2 #include<cstdio>
3 #include<cstring>
4 using namespace std;
5 #define MAXN 33
6 #define inf 1<<30
7 int map[MAXN][MAXN];
8 int n,MIN,k;
9 int num[MAXN];
10 bool mark[MAXN];
11
12 void dfs(int start,int count,int dist){
13     if(count==k){
14         MIN=min(dist,MIN);
15         return ;
16     }
17     for(int i=1;i<=k;i++){
18         if(!mark[i]){
19             mark[i]=true;
20             dfs(num[i],count+1,dist+map[start][num[i]]);
21             mark[i]=false;
22         }
23     }
24 }
25
26
27 int main(){
28     int _case;
29     while(~scanf("%d",&n)&&n){
30         for(int i=0;i<n;i++){
31             for(int j=0;j<n;j++){
32                 scanf("%d",&map[i][j]);
33             }
34         }
35         k=0,MIN=inf;
36         scanf("%d",&_case);
37         memset(mark,false,sizeof(mark));
38         while(_case--){
39             int x;
40             scanf("%d",&x);
41             if(mark[x])continue;
42             mark[x]=true;
43             num[++k]=x;
44         }
45         memset(mark,false,sizeof(mark));
46         dfs(0,0,0);
47         printf("%d\n",MIN);
48     }
49     return 0;
50 }