21 lines
551 B
Python
21 lines
551 B
Python
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#!/usr/bin/env python3
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from fractions import Fraction
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def pick(state, depth, numofc, cache={}):
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if sum(state) == depth:
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return len(state) - state.count(0)
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if state in cache:
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return cache[state]
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r = 0
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for c, num in enumerate(state):
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nws = sorted(state[:c] + (num + 1,) + state[c+1:])
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nws = tuple(nws)
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r += Fraction(numofc-num, numofc*len(state) - sum(state)) * \
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pick(nws, depth, numofc, cache)
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cache[state] = r
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return r
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r = pick(7*(0,), 20, 10)
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print(float(round(r, 9)))
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