Uva11500-Gambler's ruin

Gambler's ruin(马尔科夫过程的一个实例)

//Gambler's ruin#include <iostream>#include <cstdio>#include <cstring>#include <cmath>using namespace std;int main(){int v1,v2,at,d;while(~scanf("%d%d%d%d",&v1,&v2,&at,&d) && v1+v2+at+d){int n1 = 0,n2 = 0;if(v1%d){n1 = v1/d+1;}else{n1 = v1/d;}if(v2%d){n2 = v2/d+1;}else{n2 = v2/d;}double ans;if(at==3){ans = n1*1.0/(n1+n2);}else{double p = at/6.0;double q = 1-p;ans = (1-pow(q/p,n1))/(1-pow(q/p,n1+n2));}printf("%.1lf\n",ans*100);    }return 0;}