py_list_intersection_finder

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Entregas: py_list_intersection_finder.py con list_intersection_finder(lists). Rank 04 · nivel 2.

Qué pide (en palabras normales)

Subject (enunciado original)
Write a function that finds the intersection of multiple sorted lists.
Return a new list containing elements that appear in ALL input lists, in sorted order.

The function should:
- Return elements that appear in ALL lists
- Result should be sorted in ascending order
- Remove duplicates from the result
- Handle empty input or empty lists gracefully
- If any list is empty, the intersection is empty

Expected file: py_list_intersection_finder.py
Function signature:
def list_intersection_finder(lists: list[list[int]]) -> list[int]:

Examples:
list_intersection_finder([[1, 2, 3], [2, 3, 4], [2, 3, 5]])
=> [2, 3]
list_intersection_finder([[1, 2, 3, 4], [2, 4, 6, 8], [4, 8, 12]])
=> [4]
list_intersection_finder([[1, 1, 2, 3], [1, 2, 2, 3], [1, 2, 3, 3]])
=> [1, 2, 3]
list_intersection_finder([[1, 2, 3], [4, 5, 6]])
=> []
list_intersection_finder([])
=> []
list_intersection_finder([[1, 2, 3], []])
=> []
list_intersection_finder([[5]])
=> [5]

Solución: sets

if not lists:
    return []
common = set(lists[0])
for other in lists[1:]:
    common &= set(other)
return sorted(common)

Intersección de conjuntos encadenada. Que las listas vengan ordenadas no hace falta aprovecharlo: con sets es lineal igual y mucho más corto que la versión de punteros múltiples.

Trampas