import math import typing import collections.abc Func: typing.TypeAlias = collections.abc.Callable DistTable: typing.TypeAlias = list[list[float]] IndSeq: typing.TypeAlias = list[int] def distance_table[T](points: list[T], metric: Func[[T, T], float]) -> DistTable: return [[metric(x, y) for y in points] for x in points] def score_nearest(distances: DistTable, sample: IndSeq) -> float: return sum(min(distances[i][j] for j in sample) for i in range(len(distances))) def score_total(distances: DistTable, sample: IndSeq) -> float: return sum(sum( 0 if i in sample else distances[i][j] for j in sample ) for i in range(len(distances))) def greedy_min_seq(distances: DistTable, score_func: Func[[DistTable, IndSeq], float]) -> IndSeq: seq = [] options = set(range(len(distances))) while options: best = min(options, key=lambda o: score_func(distances, seq + [o])) seq.append(best) options.remove(best) return seq dt: DistTable = distance_table([(0, 2), (3, 2), (4, 2), (5, 0), (0, 0)], math.dist) print(greedy_min_seq(dt, score_total))