binomial function
Computes the binomial coefficient: n
choose k
.
Implementation
double binomial(int n, int k) {
if (k < 0 || n < 0 || k > n) {
return 0.0;
}
return (0.5 + exp(factorialLn(n) - factorialLn(k) - factorialLn(n - k)))
.floorToDouble();
}