long cls_random::randomBinomial(
long N,
double probability)
{
long rnd = 0;
for (long i=0;i<N;i++)
{
double pV = (double)rand()/(double)RAND_MAX;
if (pV<probability)
{
rnd++;
}
}
return rnd;
}
期望：E=
方差：V=
wiki:http://zh.wikipedia.org/wiki/%E4%BA%8C%E9%A1%B9%E5%88%86%E5%B8%83