11 lines
262 B
Groovy
11 lines
262 B
Groovy
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def factorial = { x ->
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assert x > -1
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x == 0 ? 1 : (1..x).inject(1G) { BigInteger product, BigInteger factor -> product *= factor }
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}
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def combinations = { n, k ->
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assert k >= 0
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assert n >= k
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factorial(n).intdiv(factorial(k)*factorial(n-k))
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}
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