AOJトライに関する知識知見の記録共有：Volume0-0055

タスク概要

Sequence

コード実装例

TIPS

1. 例外処理含む評価パターンを追加
2. 計算誤差比較例を追加

import pprint, sys, time

def core(arg, adv=True, n_item=10):
    a = arg[0]
    s = arg[1] if len(arg) >= 2 else 0
    if adv:
        d = pow(3, int(n_item / 2))
        odds = [d / pow(3, i) * pow(2, i) for i in range(int((n_item + 1) / 2))]
        evens = [2 * d / pow(3, i) * pow(2, i) for i in range(int(n_item / 2))]
        r = (sum(odds + evens) * a) / d
    else:
        cnst = 3 * (1 - pow(2 / 3, int(n_item / 2))) / (1 - 2 / 3) + pow(1 / 3, int(n_item / 2))
        r = a * cnst
    ret = [r, abs(r - s)]
    return ret

def app(*args):
    ret = []
    for arg in args:
        s = []
        for adv in [True, False]:
            st = time.time()
            try:
                r = core(arg, adv=adv)
            except Exception as e:
                r = e
            s.append([adv, round(time.time() - st, 6), r])
        ret.append([arg, s])
    return ret

print(sys.version)
pprint.pprint(app(
    # basic examples
    [1.0, 7.81481481],
    [2.0, 15.62962963],
    [3.0, 23.44444444],
    # additional examples
    [-1.0],
    # exceptional examples
    "例外入力"
))

実行結果

各種補足情報出力（入力値FB、デバッグログ等）含む

3.8.10 (default, Jun  2 2021, 10:49:15) 
[GCC 9.4.0]
[[[1.0, 7.81481481],
  [[True, 1.5e-05, [7.814814814814815, 4.814815213194379e-09]],
   [False, 1.9e-05, [7.818930041152263, 0.004115231152263199]]]],
 [[2.0, 15.62962963],
  [[True, 8e-06, [15.62962962962963, 3.703704010149522e-10]],
   [False, 1e-06, [15.637860082304526, 0.00823045230452557]]]],
 [[3.0, 23.44444444],
  [[True, 7e-06, [23.444444444444443, 4.444441259465748e-09]],
   [False, 2e-06, [23.456790123456788, 0.012345683456786105]]]],
 [[-1.0],
  [[True, 1.1e-05, [-7.814814814814815, 7.814814814814815]],
   [False, 2e-06, [-7.818930041152263, 7.818930041152263]]]],
 ['例外入力',
  [[True,
    1.3e-05,
    TypeError("can't multiply sequence by non-int of type 'float'")],
   [False,
    4e-06,
    TypeError("can't multiply sequence by non-int of type 'float'")]]]]

補遺

残課題（Pull Request絶賛募集中！）

1. 実行速度の改善（枝刈り、データ構造の見直し等）