Binomial coefficient
import sys
if len(sys.argv) != 3:
exit(f"Usage: {sys.argv[0]} n k")
'''
n n!
- = ---------
k k!*(n-k)!
'''
n = int(sys.argv[1])
k = int(sys.argv[2])
n_fact = 1
for i in range(1, n+1):
n_fact *= i
print(n_fact)
n_k_fact = 1
for i in range(1, n-k+1):
n_k_fact *= i
print(n_k_fact)
k_fact = 1
for i in range(1, k+1):
k_fact *= i
print(k_fact)
bc = n_fact // (k_fact * n_k_fact)
print(bc)