79 lines
2.0 KiB
Python
79 lines
2.0 KiB
Python
"""
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name: Nicholas Tamassia
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Honor Code and Acknowledgments:
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This work complies with the JMU Honor Code.
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Comments here on your code and submission.
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"""
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from dataclasses import dataclass
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from typing import Self, override
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# I don't like tuples, dataclasses ftw
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@dataclass(frozen=True)
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class KnapsackItem:
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name: str
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value: float
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weight: float
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@property
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def value_ratio(self) -> float:
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return self.value / self.weight
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@override
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def __str__(self) -> str:
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return f"{self.name}({self.value:.2f}, {self.weight:.2f})"
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@classmethod
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def parse(cls, string: str) -> Self:
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values: list[str] = string.strip().split()
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name, value, weight = values[0], float(values[1]), float(values[2])
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return cls(name, value, weight)
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def knapsack(
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capacity: int, items: list[KnapsackItem]
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) -> tuple[list[KnapsackItem], float]:
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current_capacity: float = float(capacity)
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sorted_items: list[KnapsackItem] = sorted(items, key=lambda i: -i.value_ratio)
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total_value: float = 0.0
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fractional_items: list[KnapsackItem] = []
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for item in sorted_items:
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if abs(current_capacity) < 1e-8:
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break
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name, value, weight = item.name, item.value, item.weight
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if current_capacity < weight:
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value = item.value_ratio * current_capacity
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weight = current_capacity
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fractional_items.append(KnapsackItem(name, value, weight))
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total_value += value
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current_capacity -= weight
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return fractional_items, total_value
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# All modules for CS 412 must include a main method that allows it
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# to imported and invoked from other python scripts
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def main():
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capacity: int = int(input())
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n: int = int(input())
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items: list[KnapsackItem] = [KnapsackItem.parse(input()) for _ in range(0, n)]
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fractional_items, total_value = knapsack(capacity, items)
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print(" ".join(map(str, fractional_items)))
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print(total_value)
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if __name__ == "__main__":
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main()
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