Complete Laptop allocation exercise sprint 5

Author: ike-agu

sprint-5-laptop-allocation/laptop_allocation.py

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+from dataclasses import dataclass
+from enum import Enum
+from typing import List, Dict, Optional, Tuple
+import itertools
+import sys
+
+class OperatingSystem(Enum):
+    MACOS = "macOS"
+    ARCH = "Arch Linux"
+    UBUNTU = "Ubuntu"
+
+@dataclass(frozen=True)
+class Person:
+    name: str
+    age: int
+    preferred_operating_system: List[OperatingSystem]
+
+# custom hash to hash the immutable version of the list
+    def __hash__(self) -> int:
+        return hash((self.name, self.age, tuple(self.preferred_operating_system)))
+
+
+@dataclass(frozen=True)
+class Laptop:
+    id: int
+    manufacturer: str
+    model: str
+    screen_size_in_inches: float
+    operating_system: OperatingSystem
+
+# =====define parse operating system======
+def parse_operating_system(raw: str) -> OperatingSystem:
+    normalized = raw.strip().lower()
+
+    aliases = {
+        "macos": OperatingSystem.MACOS,
+        "mac": OperatingSystem.MACOS,
+        "arch": OperatingSystem.ARCH,
+        "arch linux": OperatingSystem.ARCH,
+        "ubuntu": OperatingSystem.UBUNTU,
+    }
+
+    if normalized not in aliases:
+        valid = ", ".join(sorted(aliases.keys()))
+        print(f"Error: invalid operating system. Try one of: {valid}", file=sys.stderr)
+        sys.exit(1)
+
+    return aliases[normalized]
+
+# ======= sadness helper ============
+def sadness(person: Person, laptop: Laptop) -> int:
+    laptop_os = laptop.operating_system
+    preferences = person.preferred_operating_system
+    if laptop_os not in preferences:
+        return 100
+    return preferences.index(laptop_os)
+
+# ======= Laptop allocation ============
+def allocate_laptops(people: List[Person], laptops: List[Laptop]) -> Dict[Person, Laptop]:
+    if len(laptops) < len(people):
+        raise ValueError("Not enough laptops to allocate one per person.")
+
+    best_assignment: Optional[Dict[Person, Laptop]] = None
+    best_total_sadness: Optional[int] = None
+
+    for chosen_laptops in itertools.combinations(laptops, len(people)):
+        for permuted_laptops in itertools.permutations(chosen_laptops):
+            total = 0
+            for i in range(len(people)):
+                person = people[i]
+                laptop = permuted_laptops[i]
+                total += sadness(person, laptop)
+
+            if best_total_sadness is None or total < best_total_sadness:
+                best_total_sadness = total
+                best_assignment = {people[i]: permuted_laptops[i] for i in range(len(people))}
+
+    if best_assignment is None:
+        raise RuntimeError("Allocation failed unexpectedly.")
+
+    return best_assignment
+
+# ======define main ================
+def main() -> None:
+    laptops = [
+    Laptop(id=1, manufacturer="Dell", model="XPS", screen_size_in_inches=13.0, operating_system=OperatingSystem.ARCH),
+    Laptop(id=2, manufacturer="Dell", model="XPS", screen_size_in_inches=15.0, operating_system=OperatingSystem.UBUNTU),
+    Laptop(id=3, manufacturer="Dell", model="XPS", screen_size_in_inches=15.0, operating_system=OperatingSystem.UBUNTU),
+    Laptop(id=4, manufacturer="Apple", model="macBook", screen_size_in_inches=13.0, operating_system=OperatingSystem.MACOS),
+]
+
+    people = [
+        Person(name="Imran", age=22, preferred_operating_system=[OperatingSystem.UBUNTU, OperatingSystem.ARCH, OperatingSystem.MACOS]),
+        Person(name="Eliza", age=34, preferred_operating_system=[OperatingSystem.ARCH, OperatingSystem.UBUNTU])
+    ]
+
+    allocation = allocate_laptops(people, laptops)
+
+    # Print results
+    for person, laptop in allocation.items():
+        print(f"{person.name}:  Laptop {laptop.id} ({laptop.operating_system.value}) sadness={sadness(person, laptop)}")
+
+if __name__ == "__main__":
+    main()