Use the fact that a*b*c*d = exp(log a + log b + log c + log d)
double sum = 0.0;
double x;
for(x = n-r+1.0; x = n; x += 1.0)
sum += log(x);
for(x = 2; x = r; x += 1.0)
sum -= log(x);
result = exp(sum);
Don
On Tuesday, April 8, 2014 2:06:47 PM UTC-4, kumar raja wrote:
Hi all,
I know
Note that my example is for C(n,r), but you can use the same method for
your second formula. Just add up the logs of whatever you multiply in the
numerator and subtract the logs of the factors of the denominator. Then the
result is exp of the resulting sum.
Don
On Tuesday, April 8, 2014
What you want to do is automate the process of cancelling common factors
that you would do if you were calculating nCr by hand. Fill an array a[]
with the numerator terms, n, n-1, n-2, ..., n-r+1, and a second array b[]
with the denominator terms, 1, 2, 3, ..., r. Inside a double loop with j
