F - Dragon Ball I
1 #include <bits/stdc++.h> 2 using namespace std; 3 typedef long long ll; 4 const int maxn=5e5+10; 5 const ll inf=0x3f3f3f3f3f3f3f3f; 6 ll dis[25][maxn]; 7 ll vis[maxn]; 8 ll n,m; 9 ll head[maxn],cnt,tot; 10 struct edge{ 11 ll to,w,nxt; 12 }e[maxn]; 13 14 struct node{ 15 ll v,dis; 16 bool operator < (const node &a) const{ 17 return dis>a.dis; 18 } 19 }t,d; 20 21 void add(ll u,ll v,ll w){ 22 e[cnt].to=v; 23 e[cnt].w=w; 24 e[cnt].nxt=head[u]; 25 head[u]=cnt++; 26 } 27 void dijstra(ll k){ 28 memset(vis,0,sizeof(vis)); 29 priority_queue<node>Q; 30 t.v=k; 31 t.dis=0; 32 Q.push(t); 33 34 while(!Q.empty()){ 35 if(vis[Q.top().v]){ 36 Q.pop(); 37 continue; 38 } 39 t=Q.top(); 40 Q.pop(); 41 ll u=t.v; 42 vis[u]=1; 43 dis[tot][u]=t.dis; 44 for(ll i=head[u];i!=-1;i=e[i].nxt){ 45 ll y=e[i].to,w=e[i].w; 46 if( vis[y]==0 && dis[tot][y]>dis[tot][u]+w){ 47 dis[tot][y]=dis[tot][u]+w; 48 d.v=y; 49 d.dis=dis[tot][y]; 50 Q.push(d); 51 } 52 } 53 } 54 tot++; 55 } 56 57 58 59 signed main() 60 { 61 memset(head,-1,sizeof(head)); 62 memset(dis,0x3f,sizeof(dis)); 63 cin>>n>>m; 64 for(ll i=0;i<m;i++){ 65 ll u,v,w; 66 cin>>u>>v>>w; 67 add(u,v,w); 68 add(v,u,w); 69 } 70 tot=0; 71 ll ans=inf; 72 ll b[10]; 73 ll a[10]={1,2,3,4,5,6,7,8,9}; 74 dijstra(1); //到自己一开始的最单路//dis[0][...]各点到1的距离 75 for(ll i=1;i<=7;i++){ 76 cin>>b[i]; //龙珠位置 77 dijstra(b[i]); //到龙珠的最短路//dis[1~7][...]各点到1~7个龙珠的最短路径 78 } 79 do{ //用全排列求路径 80 ll now=dis[0][b[a[0]]]; 81 now += dis[a[0]][b[a[1]]]; 82 now += dis[a[1]][b[a[2]]]; 83 now += dis[a[2]][b[a[3]]]; 84 now += dis[a[3]][b[a[4]]]; 85 now += dis[a[4]][b[a[5]]]; 86 now += dis[a[5]][b[a[6]]]; 87 ans = min(ans,now); 88 }while(next_permutation(a,a+7)); 89 if( ans<inf ) cout<<ans<<endl; 90 else cout<<"-1"<<endl; 91 return 0; 92 }
