Python/dynamic_programming/fractional_knapsack.py
Ankur Chattopadhyay 7592cba417 psf/black code formatting (#1421)
* added sol3.py for problem_20

* added sol4.py for problem_06

* ran `black .` on `\Python`
2019-10-22 19:13:48 +02:00

28 lines
582 B
Python

from itertools import accumulate
from bisect import bisect
def fracKnapsack(vl, wt, W, n):
"""
>>> fracKnapsack([60, 100, 120], [10, 20, 30], 50, 3)
240.0
"""
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
doctest.testmod()