19/01/26 05:11:41.67 iYrqGgfh.net
>>901 C++
inline uint64_t gcd(uint64_t a, uint64_t b) {
uint64_t r;
while ((r = a % b) != 0) {
a = b; b = r;
}
return b;
}
uint64_t binomial(uint64_t n, uint64_t m) {
if (n < m)
return 0;
m = (m > n / 2) ? n - m : m;
uint64_t result = 1;
for (uint64_t i = 1; i <= m; i++, n--) {
uint64_t d = gcd(result, i);
result /= d;
result *= n / (i / d);
}
return result;
}