hdu_5711_Ingress(TSP+贪心)

题目连接:hdu5711

这题是 HDU 女生赛最后一题,TSP+贪心,确实不好想,看了wkc巨巨的题解,然后再做的

题解传送门:Ingress

 1 #include<cstdio>
 2 #include<queue>
 3 #include<algorithm>
 4 #define F(i,a,b) for(int i=a;i<=b;i++)
 5 using namespace std;
 6 typedef pair<int,int> P;
 7 inline void up(int &x,int y){if(x>y)x=y;}
 8 
 9 int ic=1,t,n,m,ans,k,en,l,u,v,c,inf=1e9+7;
10 int a[20],b[20],g[20][20],dp[1<<16][17],vis[1<<16];
11 
12 int main(){
13     scanf("%d",&t);
14     while(t--){
15         scanf("%d%d%d%d",&n,&m,&k,&l);en=(1<<n)-1;
16         F(i,0,n)F(j,0,n)g[i][j]=(i==j?0:inf);
17         F(i,0,en)F(j,0,n)dp[i][j]=inf;
18         F(i,0,en)vis[i]=0;
19         F(i,1,n)scanf("%d",a+i);
20         F(i,1,n)scanf("%d",b+i);
21         F(i,1,m)scanf("%d%d%d",&u,&v,&c),up(g[u][v],c),up(g[v][u],c);
22         F(kk,0,n)F(i,0,n)F(j,0,n)up(g[i][j],g[i][kk]+g[kk][j]);//Floyd
23         dp[0][0]=0,ans=0;
24         F(i,0,en){
25             F(j,0,n)if(dp[i][j]<=l){
26                 if(dp[i][j]+g[j][0]<=l)vis[i]=1;
27                 F(q,1,n)if(q==j||i&1<<q-1)continue;
28                 else up(dp[i|1<<q-1][q],dp[i][j]+g[j][q]);
29             }
30             if(vis[i]){
31                 priority_queue<P>Q;
32                 F(j,1,n)if(i&1<<j-1)Q.push(P(a[j],b[j]));
33                 if(Q.empty())continue;
34                 int tmp=0;
35                 F(j,1,k){
36                     tmp+=Q.top().first;
37                     Q.push(P(max(Q.top().first-Q.top().second,0),Q.top().second));
38                     Q.pop();
39                 }
40                 ans=max(ans,tmp);
41             }
42         }
43         printf("Case %d: %d\n",ic++,ans);
44     }
45     return 0;
46 }
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posted @ 2016-07-02 15:20  bin_gege  阅读(233)  评论(0编辑  收藏  举报