给定一组单词,我们需要找到anagram单词并使用最佳算法单独显示每个类别.
输入:
man car kile arc none like
Run Code Online (Sandbox Code Playgroud)
输出:
man
car arc
kile like
none
Run Code Online (Sandbox Code Playgroud)
我现在开发的最佳解决方案是基于散列表,但我正在考虑将anagram字转换为整数值的等式.
示例:man =>'m'+'a'+'n'但这不会给出唯一值.
有什么建议吗?
请参阅C#中的以下代码:
string line = Console.ReadLine();
string []words=line.Split(' ');
int[] numbers = GetUniqueInts(words);
for (int i = 0; i < words.Length; i++)
{
if (table.ContainsKey(numbers[i]))
{
table[numbers[i]] = table[numbers[i]].Append(words[i]);
}
else
{
table.Add(numbers[i],new StringBuilder(words[i]));
}
}
Run Code Online (Sandbox Code Playgroud)
问题是如何开发GetUniqueInts(string [])方法.
在块日历的背面,我发现了以下谜语:
你可以用"教科书"这个词的字母做出多少4个字母或更多的常用英文单词(每个字母只能使用一次).
我想出的第一个解决方案是:
from itertools import permutations
with open('/usr/share/dict/words') as f:
words = f.readlines()
words = map(lambda x: x.strip(), words)
given_word = 'textbook'
found_words = []
ps = (permutations(given_word, i) for i in range(4, len(given_word)+1))
for p in ps:
for word in map(''.join, p):
if word in words and word != given_word:
found_words.append(word)
print set(found_words)
Run Code Online (Sandbox Code Playgroud)
这给出了结果,set(['tote', 'oboe', 'text', 'boot', 'took', 'toot', 'book', 'toke', 'betook'])但在我的机器上花费了超过7分钟.
我的下一次迭代是:
with open('/usr/share/dict/words') as f:
words = f.readlines()
words = map(lambda x: x.strip(), words) …Run Code Online (Sandbox Code Playgroud) 我写了一篇关于Code Review的问题的灾难,询问为什么Python程序员通常通过比较字符串与自身的反转来测试字符串是否为回文,而不是更复杂的算法,假设正常方式会更快.
这是pythonic方式:
def is_palindrome_pythonic(word):
# The slice requires N operations, plus memory
# and the equality requires N operations in the worst case
return word == word[::-1]
Run Code Online (Sandbox Code Playgroud)
以下是我尝试以更有效的方式完成此任务:
def is_palindrome_normal(word):
# This requires N/2 operations in the worst case
low = 0
high = len(word) - 1
while low < high:
if word[low] != word[high]:
return False
low += 1
high -= 1
return True
Run Code Online (Sandbox Code Playgroud)
我希望正常的方式比pythonic方式更快.例如,请参阅这篇精彩文章
timeit然而,与它同步,带来了完全相反的结果:
setup = '''
def is_palindrome_pythonic(word):
# ...
def is_palindrome_normal(word):
# …Run Code Online (Sandbox Code Playgroud)