Python/dynamic_programming/fractional_knapsack.py

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from bisect import bisect
from itertools import accumulate
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def fracKnapsack(vl, wt, W, n):
"""
>>> fracKnapsack([60, 100, 120], [10, 20, 30], 50, 3)
240.0
"""
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r = list(sorted(zip(vl, wt), key=lambda x: x[0] / x[1], reverse=True))
vl, wt = [i[0] for i in r], [i[1] for i in r]
acc = list(accumulate(wt))
k = bisect(acc, W)
return (
0
if k == 0
else sum(vl[:k]) + (W - acc[k - 1]) * (vl[k]) / (wt[k])
if k != n
else sum(vl[:k])
)
if __name__ == "__main__":
import doctest
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doctest.testmod()