Python - Case Study Word Play(Forbidden letters)

Think Python

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• Python 3.5 (プログラミング言語)

Think Python (Allen B. Downey (著)、 O'Reilly Media)のChapter 9.(Case Study Word Play)のExercises 9-3(No. 1961)を取り組んでみる。

Exercises 9-3(No. 1961)

コード(Emacs)

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

def avoids(word, forbidden_letters):
    for letter in forbidden_letters:
        if letter in word:
            return False
    return True

if __name__ == '__main__':
    letters = [chr(letter) for letter in range(ord('a'), ord('z') + 1)]
    # 5だと時間がかかったから 2 に変更
    # (それでも時間がかかったからアルゴリズムの変更が必要かも。。)
    forbidden_letters = [a + b
                         for a in letters
                         for b in letters
                         if a < b]
                         # for d in letters
                         # for e in letters
                         # if a < b < c < d < e]
    print(len(forbidden_letters))
    n = 0
    combinations = set()
    with open('words.txt') as f:
        words = f.read().split()
    print(len(words))
    for letters in forbidden_letters:
        count = 0            
        for word in words:
            if avoids(word, letters):
                count += 1
        if count > n:
            combinations = {letters}
            n = count
        elif count == n:
            combinations.add(letters)
            
    print(combinations, n)

入出力結果(Terminal, IPython)

$ ./sample3.py
325
113809
{'jq'} 110435
$