hdu 2059 龟兔赛跑

http://acm.hdu.edu.cn/showproblem.php?pid=2059

#include < iostream >
using   namespace  std;
struct  Node
{
    double tim;
    double ls;
} ;
int  main()
{
    double S;
    while(cin>>S)
    {
        int n,i,j;
        double L,time,rv,tortoiseC,tortoiseQ,pos[103];
        Node dp[103],temp;
        double d,d1,d2,t1,t2;
        cin>>n>>L>>time;
        cin>>rv>>tortoiseQ>>tortoiseC;
        for(i=1;i<=n;i++)
            cin>>pos[i];
        if(tortoiseQ<=tortoiseC)//骑车不如蹬车
        {
            if(S/tortoiseC>S/rv)
                cout<<"Good job,rabbit!"<<endl;
            else
                cout<<"What a pity rabbit!"<<endl;
            continue;
        }
        dp[0].tim=0;
        dp[0].ls=L;
        pos[0]=0;//一定要赋初值，否则其默认初值为负数，因为是double类型
        pos[n+1]=S;
        for(i=1;i<=n+1;i++)
        {
            dp[i].tim=100000000;
            dp[i].ls=0;
            for(j=0;j<i;j++)//从出发点开始到i站之前选择一个最优的
            {
                d=pos[i]-pos[j];
                if(dp[j].ls>=d)//无需充电
                {
                    temp.tim=dp[j].tim+d/tortoiseQ;
                    temp.ls=dp[j].ls-d;
                }
                else
                {
                    t1=dp[j].tim+dp[j].ls/tortoiseQ+(d-dp[j].ls)/tortoiseC;
                    d1=0;
                    if(L>=d)//充电够用情况
                    {
                        t2=dp[j].tim+time+d/tortoiseQ;
                        d2=L-d;
                    }
                    else//充电不够用情况
                    {
                        t2=dp[j].tim+time+L/tortoiseQ+(d-L)/tortoiseC;
                        d2=0;
                    }

                    if(t1<t2)//选择时间最少的
                    {
                        temp.tim=t1;
                        temp.ls=d1;
                    }
                    else
                    {
                        temp.tim=t2;
                        temp.ls=d2;
                    }
                }
                if(temp.tim < dp[i].tim)
                {
                    dp[i].tim=temp.tim;
                    dp[i].ls=temp.ls;
                }
            }//for(j=0;j<i;j++)
        }//for(i=1;i<=n+1;i++)
        if(dp[n+1].tim>S/rv)
            cout<<"Good job,rabbit!"<<endl;
        else
            cout<<"What a pity rabbit!"<<endl;
    }
    return 0;
}