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@rougier
Created January 25, 2016 09:50
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A fast way to calculate binomial coefficients in python (Andrew Dalke)
def binomial(n, k):
"""
A fast way to calculate binomial coefficients by Andrew Dalke.
See http://stackoverflow.com/questions/3025162/statistics-combinations-in-python
"""
if 0 <= k <= n:
ntok = 1
ktok = 1
for t in xrange(1, min(k, n - k) + 1):
ntok *= n
ktok *= t
n -= 1
return ntok // ktok
else:
return 0
@keithbriggs
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The intention was that this should use only integer arithmetic (my version was converted from C code which used /=). So yes, this is better:

def binomial(n, k):
    if not 0 <= k <= n:
        return 0
    b = 1
    for t in range(min(k, n-k)):
        b *= n
        b //= t+1
        n -= 1
    return b

@VJlaxmi
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VJlaxmi commented Dec 14, 2022

def C(n, k): if k == 0 or k == n: return 1 else: return C(n-1, k) + C(n-1, k-1)

@keithbriggs
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It is much more efficient NOT to use recursion.

@vishakhjk
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vishakhjk commented Mar 19, 2023

Try this....a short way by importing comb from math library

from math import comb
def coefficient(n,r):
return comb(n,r)
print(coefficient(5,2))

Change coefficient values to your desire

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