HDU 3076 ssworld vs DDD (probability DP)

///题意：/// A,B掷骰子，对于每一次点数大者胜，平为和，A先胜了m次A赢，B先胜了n次B赢。///p1表示a赢，p2表示b赢，p=1-p1-p2表示平局///a赢得概率 比一次p1 两次p0*p1 三次 p0^2*p1,即A赢的概率为p1+p*p1+p^2*p1+...p^n*p1,n->无穷///即a_win=p1/(1-p);b_win=p2/(1-p);///dp[i][j]表示a赢了j次，b赢了i次的概率///dp[i][j]=dp[i-1][j]*b_win+dp[i][j-1]*a_win;///ps:（两人的血量要换一换，数据错了）# include <stdio.h># include <algorithm># include <iostream># include <string.h>using namespace std;double dp[2010][2010];int main(){    int i,j,n,m;    double p1,p2,p,a_win,b_win,a[10],b[10];    while(~scanf("%d%d",&m,&n))    {        for(i=1; i<=6; i++)            scanf("%lf",&a[i]);        for(i=1; i<=6; i++)            scanf("%lf",&b[i]);        a_win=0;        b_win=0;        for(i=2; i<=6; i++)        {            for(j=1; j<i; j++)            {                a_win+=a[i]*b[j];                b_win+=b[i]*a[j];            }        }        p1=a_win;        p2=b_win;        p=1-p1-p2;        if(p==1)            printf("0.000000\n");//为平局，a不可能赢        else        {            a_win=p1/(1-p);            b_win=p2/(1-p);        }        memset(dp,0,sizeof(dp));        dp[0][0]=1;        for(i=0; i<n; i++) //b赢得次数        {            for(j=0; j<m; j++) //a赢得次数            {                if(i==0&&j==0)                    continue;                dp[i][j]=0;                if(j>0)                    dp[i][j]+=dp[i][j-1]*a_win;                if(i>0)                    dp[i][j]+=dp[i-1][j]*b_win;            }        }        double ans=0;        for(i=0; i<n; i++)            ans+=dp[i][m-1]*a_win;        if(ans>1)            ans=1;        printf("%.6lf\n",ans);    }    return 0;}

HDU 3076 ssworld vs DDD (probability DP)