19/01/26 03:39:53.55 mo79YSSI.net
>>901 Ruby
c = -> (n, k, m = []) {
m[n] = [1] unless m[n]
k = n - k if n < k * 2
return m[n][k] if m[n][k]
m[n][k] = c[n - 1, k - 1, m] + c[n - 1, k, m]
}
p c[5, 2] # => 10
p c[100, 50] # => 100891344545564193334812497256
>>903
undefined - 1n でエラーが起きているので
const c = (n, r) => p(n, r) / p(r, r);