lvxingshang_wenti

#include<cstdio>
#include<string.h>
int citynum,edgenum;//点数和边数
int map_[20][20];
int bestpath[20];
int themost_liubi_path[20];
int themost_xiao_cost=0;
int maxnum=9999999;
int nowbestcost=maxnum;
void wodeswap(int &a,int &b){
    //printf("交换前：a的的值%d\t b的值%d\n",a,b);
    int temp;
    temp=a^b;
    a=temp^a;
    b=temp^b;
   // printf("a的的值%d\t b的值%d\n",a,b);
}
void dfs(int i,int currentcost){
    if(i==citynum){

         //   printf("bestpath[最后一个数是]:%d\n",bestpath[citynum]);
   /* if((map_[i-1][bestpath[citynum]]!=-1))
    {
        printf("第一个条件满足\n");
    }
    if(map_[bestpath[citynum]][1]!=-1){
        printf("第二个条件满足\n");
    }*/
        if(map_[bestpath[i-1]][bestpath[citynum]]!=-1&&map_[bestpath[citynum]][1]!=-1&&currentcost+map_[bestpath[i-1]][bestpath[citynum]]+map_[bestpath[citynum]][1]<nowbestcost){
                nowbestcost=currentcost+map_[bestpath[i-1]][bestpath[citynum]]+map_[bestpath[citynum]][1];
               // printf("%d\t%d\n",map_[bestpath[i-1]][bestpath[citynum]],map_[bestpath[citynum]][1]);
                //  printf("加上最后两段前的最小花费:%d\n",currentcost);
               // printf("最小花费:%d\n",nowbestcost);
               // printf("完成一个次解：这个解的结果是:%d\n",nowbestcost);
            for(int p=1;p<=citynum;++p){
                    themost_liubi_path[p]=bestpath[p];
                  //  printf("%d\t",bestpath[p]);
            }
             //    printf("\n");
        }

    }
    else{
        //    printf("这是第%d步\n",i);
        for(int k=i;k<=citynum;++k){//遍历剩下的城市
         //   printf("这是第%d步",i);printf("参与循环的城市%d\n",bestpath[k]);

           // printf("bestpath2的值%d\n",bestpath[2]);
       //    printf("第一个条件的值：%d",map_[bestpath[i-1]][k]);
       //    printf("bestpath[i-1]=%d\tk=%d\n",bestpath[i-1],k);

            if((map_[bestpath[i-1]][bestpath[k]]!=-1)&&(currentcost+map_[bestpath[i-1]][bestpath[k]])<nowbestcost){
               //     printf("这是第%d步",i);printf("能进来的k变量%d\n",k);
                  //  printf("交换前的两个值%d\t%d  \t i的值：%d \tk的值:%d\n",bestpath[i],bestpath[k],i,k);
                wodeswap(bestpath[i],bestpath[k]);
              //   printf("交换完了之后：bestpath[3]的值%d\n",bestpath[3]);
                currentcost=currentcost+map_[bestpath[i-1]][bestpath[i]];

                dfs(i+1,currentcost);
                // printf("laile la ma\n");
                 currentcost=currentcost-map_[bestpath[i-1]][bestpath[i]];

                 wodeswap(bestpath[i],bestpath[k]);

            }

          //   printf("这是第%d步",i);printf("走完if之后的变量k：%d\n",k);
        }
    }
}

int main (){
   /* int a=50;
    wodeswap(a,a);
    printf("huan:%d  %d\n",a,a);
    return 0;*/
    int casenum;
    scanf("%d",&casenum);


    for(int i=1;i<=casenum;++i){
memset(map_,-1,sizeof(map_));
           nowbestcost=maxnum;
        scanf("%d%d",&citynum,&edgenum);
        int rows,cols;
        for(int j=1;j<=edgenum;++j){
            scanf("%d%d",&rows,&cols);
            scanf("%d",&map_[rows][cols]);
           map_[cols][rows]=map_[rows][cols];
        }
        /*for(int op=1;op<=citynum;++op){
        for(int op2=1;op2<=citynum;++op2){
            printf("%d ",map_[op][op2]);
        }
        puts("");
        }*/
        for(int j=0;j<=citynum;++j){
            bestpath[j]=j;
        }
        nowbestcost=maxnum;
        int currentcost;
        dfs(2,0);


       if(nowbestcost==maxnum){
                 printf("Case %d: -1\n",i);
        }
        else{
            printf("Case %d: %d\n",i,nowbestcost);
        }
         /* printf("路线：");
        for(int k=1;k<=citynum;++k){
          printf("\t%d",themost_liubi_path[k]);
        }*/
    }


}