mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-12-18 09:10:16 +00:00
aeee0f42a5
* Add doctests for fractional knapsack * Update greedy_methods/fractional_knapsack.py Co-authored-by: Christian Clauss <cclauss@me.com> * Run doctests * Update greedy_methods/fractional_knapsack.py Co-authored-by: Christian Clauss <cclauss@me.com> * Update greedy_methods/fractional_knapsack.py --------- Co-authored-by: Christian Clauss <cclauss@me.com>
52 lines
1.4 KiB
Python
52 lines
1.4 KiB
Python
from bisect import bisect
|
|
from itertools import accumulate
|
|
|
|
|
|
def frac_knapsack(vl, wt, w, n):
|
|
"""
|
|
>>> frac_knapsack([60, 100, 120], [10, 20, 30], 50, 3)
|
|
240.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 10, 4)
|
|
105.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 8, 4)
|
|
95.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6], 8, 4)
|
|
60.0
|
|
>>> frac_knapsack([10, 40, 30], [5, 4, 6, 3], 8, 4)
|
|
60.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 0, 4)
|
|
0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 8, 0)
|
|
95.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], -8, 4)
|
|
0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 8, -4)
|
|
95.0
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 800, 4)
|
|
130
|
|
>>> frac_knapsack([10, 40, 30, 50], [5, 4, 6, 3], 8, 400)
|
|
95.0
|
|
>>> frac_knapsack("ABCD", [5, 4, 6, 3], 8, 400)
|
|
Traceback (most recent call last):
|
|
...
|
|
TypeError: unsupported operand type(s) for /: 'str' and 'int'
|
|
"""
|
|
|
|
r = 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()
|