def binomial_coefficient(n, r):
"""
Find binomial coefficient using pascals triangle.
>>> binomial_coefficient(10, 5)
252
"""
c = [0 for i in range(r + 1)]
# nc0 = 1
c[0] = 1
for i in range(1, n + 1):
# to compute current row from previous row.
j = min(i, r)
while j > 0:
c[j] += c[j - 1]
j -= 1
return c[r]
print(binomial_coefficient(n=10, r=5))