zoukankan      html  css  js  c++  java
  • hdu3001 Travelling

    Travelling

    Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
    Total Submission(s): 2520    Accepted Submission(s): 735

    Problem Description
    After coding so many days,Mr Acmer wants to have a good rest.So travelling is the best choice!He has decided to visit n cities(he insists on seeing all the cities!And he does not mind which city being his start station because superman can bring him to any city at first but only once.), and of course there are m roads here,following a fee as usual.But Mr Acmer gets bored so easily that he doesn't want to visit a city more than twice!And he is so mean that he wants to minimize the total fee!He is lazy you see.So he turns to you for help.
     
    Input
    There are several test cases,the first line is two intergers n(1<=n<=10) and m,which means he needs to visit n cities and there are m roads he can choose,then m lines follow,each line will include three intergers a,b and c(1<=a,b<=n),means there is a road between a and b and the cost is of course c.Input to the End Of File.
     
    Output
    Output the minimum fee that he should pay,or -1 if he can't find such a route.
     
    Sample Input
    2 1 1 2 100 3 2 1 2 40 2 3 50 3 3 1 2 3 1 3 4 2 3 10
     
    Sample Output
    100 90 7
     
    用三进制来进行壮态压缩,这样就可以大大减少状态数,在预处理一下,就可以了,其次,每一个点都要走一次!
    #include <iostream>
    #include <stdio.h>
    using namespace std;
    int threenum[11]={1,3,9,27,81,243,729,2187,6561,19683,59049};
    #define inf 0x4f4f4f4f
    int dp[600000][15],n,m;
    int threeevery[600000][15],dis[15][15];
    int fmin(int x,int y){if(x<y)return x;return y;}
    void makethree()//先预处理,算出所有的值
    {
        int i,temp,j;
        for(i=0;i<threenum[10];i++)//3的11次
        {
            temp=i;
           for(j=0;j<10;j++)
           {
               threeevery[i][j]=temp%3;
               temp=temp/3;
           }
        }
    
    }
    void init()
    {
        int i,j,s,e,val;
        for(i=0;i<threenum[n];i++)
        {
            for(j=0;j<n;j++)
            {
                dp[i][j]=inf;
            }
        }
        for(i=0;i<n;i++)
            for(j=0;j<n;j++)
                {
                    dis[i][j]=inf;
                }
          for(i=0;i<n;i++)
        {
            dp[threenum[i]][i]=0;//到自已的点初始化为0
        }
    
        for(i=0;i<m;i++)
        {
    
                scanf("%d%d%d",&s,&e,&val);
                s--;e--;//全部从0开
                 if(val<dis[s][e])
                    dis[s][e]=dis[e][s]=val;//排除重边取最小值
    
        }
    
    }
    int makedp()
    {
        int i,j,k,minx;
        bool flag;
        minx=inf;
        for(i=0;i<threenum[n];i++)//对于每一位都要计算
        {
            flag=true;//标记是否每一个点都已经经过
            for(j=0;j<n;j++)
            {
                if(threeevery[i][j]==0)//是这个点没有走
                    flag=false;
                if(dp[i][j]==inf)//没有走过
                {
                    continue;
                }
                for(k=0;k<n;k++)//加入k这个点
                {
                    if((j==k)||threeevery[i][k]>=2||(dis[j][k]==inf))//自已到自已的地方,经过超过两次,不相连通去掉
                    continue;
                    dp[i+threenum[k]][k]=fmin(dp[i+threenum[k]][k],dp[i][j]+dis[j][k]);//从j到k
                }
    
            }
            if(flag)//满足条件,对最小值进行更新
            {
                for(j=0;j<n;j++)
                {
                    minx=fmin(dp[i][j],minx);
                }
            }
        }
        if(minx==inf)
        {
           minx=-1;
        }
    
        printf("%d
    ",minx);
        return 1;
    }
    int main()
    {
        makethree();
        while(scanf("%d%d",&n,&m)!=EOF)
        {
            init();
            makedp();
        }
        return 0;
    }
    

     


  • 相关阅读:
    vi 编辑内容中查找字符位置
    使用 Oracle GoldenGate 在 Microsoft SQL Server 和 Oracle Database 之间复制事务
    EBS R12 更改SYSADMIN密码
    两种步骤 更改 EBS R12界面LOGO以及内容
    Get Current LOV Query SQL
    Oracle Gateways透明网关访问SQL Server
    Oracle 数据集成的实际解决方案
    将SQLServer2005中的数据同步到Oracle中
    ogg实现oracle到sql server 2005的同步
    wince和window mobile winphone
  • 原文地址:https://www.cnblogs.com/snake-hand/p/3187193.html
Copyright © 2011-2022 走看看