08/09/08 23:59:34
>>549
double odds(double p, double q, int m, int n)
{
if(m==0) return 1.0;
if(n==0) return 0.0;
return ( p*q*odds(p,q,m-1,n-1) + p*(1-q)*odds(p,q,m-1,n) + (1-p)*q*odds(p,q,m,n-1) ) / (p+q-p*q);
}
//
// F(m,n) = p*q*F(m-1,n-1) +p*(1-q)*F(m-1,n) +(1-p)*q*F(m-1,n) +(1-p)*(1-q)*F(m,n)
// 上の式を、F(m,n) について解く
//