hdu 2489 最小生成树状态压缩枚举

思路：

直接状态压缩暴力枚举

#include<iostream>

#include<algorithm>

#include<cstdio>

#include<cstring>

#define Maxn 30

#define inf 10000000

using namespace std;

int ans,n,m;

int c,d;

int map[Maxn][Maxn];

int lis[Maxn],node[Maxn];

int val[1<<17],sum[1<<17];

int main()

{

    int i,j;

    while(scanf("%d%d",&n,&m),n||m){

        memset(val,48,sizeof(val));

        memset(sum,0,sizeof(sum));

        c=1000000,d=1;

        for(i=1;i<=n;i++)

            scanf("%d",&node[i]);

        memset(map,0,sizeof(map));

        for(i=1;i<=n;i++){

            for(j=1;j<=n;j++){

                scanf("%d",&map[i][j]);

            }

        }

        int N=1<<n;

        N-=1;

        int cnt=0;

        val[0]=0;

        for(i=0;i<=n;i++)

            val[1<<i]=0;

        for(i=1;i<=N;i++){

            cnt=0;

            for(j=0;j<n;j++){

                if(i&(1<<j)) lis[++cnt]=j+1,sum[i]+=node[j+1];

            }

            if(cnt>m) continue;

            if(cnt==m)

            {

                int a=val[i],b=sum[i];

                if(a*d<c*b){

                    ans=i;

                    c=a;

                    d=b;

                }

            }

            int temp;

            for(j=0;j<n;j++){

                if(((1<<j)&i)==0){

                    temp=inf;

                    for(int k=1;k<=cnt;k++){

                        temp=min(temp,map[j+1][lis[k]]);

                    }

                    val[i|(1<<j)]=min(val[i]+temp,val[i|(1<<j)]);

                }

            }

        }

        int num=1;

        for(j=0;j<n;j++)

            if((1<<j)&ans){

                printf("%d",j+1);

                if(num!=m)

                    printf(" ");

                num++;

            }

        printf("\n");

    }

    return 0;

}