poj2288汉密尔顿路

抄书

#include<stdio.h>
#include<iostream>
#include<string.h>

#define maxn 13
#define maxstatus 1<<13
using namespace std;
typedef long long LL ;
LL dp[maxstatus][maxn][maxn];
LL ways[maxstatus][maxn][maxn];

int value[maxn];
bool link[maxn][maxn];

int nislands;
LL maxvalue;
LL maxways;

void  init()
{
    int nbridges;
    int i;int row;int col;
    scanf("%d%d",&nislands,&nbridges);
    for(int i=0;i<nislands;i++){
        scanf("%d",value+i);
    }
    if(nislands==1) return ;
    memset(dp,-1,sizeof(dp));
    memset(ways,0,sizeof(ways));
    memset(link,0,sizeof(link));
    for(int i=0;i<nbridges;i++){
        scanf("%d%d",&row,&col);
        row--;col--;
        link[row][col]=1;link[col][row]=1;
        dp[(1<<row)|(1<<col)][row][col]=dp[(1<<col)|(1<<row)][col][row]=value[col]+value[row]+value[col]*value[row];
        ways[(1<<row)|(1<<col)][row][col]=ways[(1<<row)|(1<<col)][col][row]=1;
    }
}

void Dp()
{
    int s;int i;int j;int k;
    LL temp; LL nextstatus;
    if(nislands==1) {
        maxvalue=value[0];maxways=1;
        return ;
    }
    for(s=0;s<(1<<nislands);s++){
        for(i=0;i<nislands;i++){
            if(s&(1<<i)){
                for(j=0;j<nislands;j++){
                    if(i!=j&&(s&(1<<j))&&dp[s][i][j]>-1){
                        for(k=0;k<nislands;k++){
                            if(!(s&(1<<k))&&link[i][k]==1){
                                nextstatus=s|(1<<k);
                                temp=dp[s][i][j]+value[k]+value[k]*value[i];
                                if(link[j][k]==1)
                                    temp+=value[k]*value[j]*value[i];
                                if(dp[nextstatus][k][i]==temp){
                                    ways[nextstatus][k][i]+=ways[s][i][j];
                                }
                                else if(dp[nextstatus][k][i]<temp){
                                    ways[nextstatus][k][i]=ways[s][i][j];
                                    dp[nextstatus][k][i]=temp;
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    maxvalue=-1;maxways=0;
    s=(1<<nislands)-1;
    for(int i=0;i<nislands;i++){
        for(int j=0;j<nislands;j++){
            if(!link[i][j]) continue;
            if(dp[s][i][j]==maxvalue) maxways+=ways[s][i][j];
            else if(dp[s][i][j]>maxvalue){
                maxvalue=dp[s][i][j];
                maxways=ways[s][i][j];
            }
        }
    }
    maxways=maxways/2;
}

int main()
{
    int i;int cases;
    scanf("%d",&cases);
    for(int i=0;i<cases;i++){
        init();
        Dp();
        if(maxvalue==-1) printf("0 0\n");
        else cout<<maxvalue<<maxways<<endl;
    }
    return 0;
}

poj2288汉密尔顿路,布布扣,bubuko.com