【CODEVS】2800 送外卖

#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int inf=0x3f3f3f3f,maxn=18;
int mp[maxn][maxn],f[maxn][(1<<maxn)],n;
int main()
{
    scanf("%d",&n);n++;
    for(int i=1;i<=n;i++)
     for(int j=1;j<=n;j++)
      scanf("%d",&mp[i][j]);
    for(int i=1;i<=n;i++)mp[i][i]=0;
    for(int k=1;k<=n;k++)
     for(int i=1;i<=n;i++)
      for(int j=1;j<=n;j++)
       if(mp[i][j]>mp[i][k]+mp[k][j])mp[i][j]=mp[i][k]+mp[k][j];
    memset(f,0x3f,sizeof(f));
    f[1][0]=0;
    for(int i=0;i<=(1<<n)-1;i++)
     for(int j=1;j<=n;j++)
      for(int k=1;k<=n;k++)
       if(i&(1<<(j-1)))f[j][i]=min(f[j][i],f[k][i-(1<<(j-1))]+mp[k][j]);
    printf("%d",f[1][(1<<n)-1]);
    return 0;
}