題目連接:http://acm.hdu.edu.cn/showproblem.php?pid=5418
題意:給你n個點,和一些邊,找一條路徑經過全部的點,並回到起點,問最小的花費是多少,
題解:m<=1e5,n<16,說明有多邊,需要處理一下,處理完用floyd跑一下,然後進行狀態壓縮dp。
#include<cstdio>
#define F(i,a,b) for(int i=a;i<=b;i++)
inline void up(int &x,int y){if(x>y)x=y;}
int dp[1<<16][17],g[17][17],inf=1<<29,n,m,t,u,v,c,end,ans;
int main(){
scanf("%d",&t);
while(t--){
scanf("%d%d",&n,&m),end=(1<<n)-1,ans=inf;
F(i,1,n)F(j,1,n)g[i][j]=(i==j?0:inf);
F(i,1,m)scanf("%d%d%d",&u,&v,&c),up(g[u][v],c),up(g[v][u],c);
F(k,1,n)F(i,1,n)F(j,1,n)up(g[i][j],g[i][k]+g[k][j]);//Floyd
F(i,1,end)F(j,1,n)dp[i][j]=inf;
dp[1][1]=0;
F(i,1,end)F(j,1,n)if(dp[i][j]!=inf)F(k,2,n)
if(k==j||i&1<<k-1)continue;
else up(dp[i|1<<k-1][k],dp[i][j]+g[j][k]);
F(i,1,n)up(ans,dp[end][i]+g[i][1]);
printf("%d\n",ans);
}
return 0;
}