42 lines
881 B
Python
42 lines
881 B
Python
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#!/usr/bin/env python
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def p(n,k):
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if k == 0:
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return 0
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elif n == k or k == 1:
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return 1
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elif n < k:
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return 0
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else:
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return p(n-1,k-1) + p(n-k,k)
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def s(n,k):
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if n == k:
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return 1
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elif k == 0:
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return 0
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elif n < k:
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return 0
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else:
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return s(n-1,k-1) + (n-1)*s(n-1,k)
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def S(n, k):
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if n == k:
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return " S_{" + n + "," + k + "} "
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# return 1
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elif k == 1:
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return " S_{" + n + "," + k + "} "
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# return 1
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elif k == 0:
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return " S_{" + n + "," + k + "} "
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# return 0
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elif n < k:
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return " S_{" + n + "," + k + "} "
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# return 0
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else:
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return " S_{" + str(n-1) + "," + str(k-1) + "} + " + str(k) + " * S_{" + str(n-1) + "," + str(k) + "} "
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# return S(n-1,k-1) + k * S(n-1,k)
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print(S(5,3))
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# print(p(10,4))
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