ブルートフォースアルゴリズムと文字列マッチング？

Question

私は次のことを行う方法と、本当に困惑しているん：

Your main program should read in two strings from the user (one string at a time, so you will have two separate strings). The first line (string) that is read is called the text string, and the second line (string) is called the pattern string.

Then you will implement a function, called match that implements the simple brute force pattern matching. This function takes two strings (the text string and the pattern string), and returns True if the pattern string matches some portion of the text string: otherwise, the function returns False .

Your main program must keep doing the following task: ask the user for a text string and a pattern string and print a message that states whether the pattern was found in the text or not. The program stops when the user enters qqq as the text string (your program must stop regardless of the case of the letter).

これまでのところ、私は仕事を入力したコードのどれも。私を助けてください！

Answer 1

だから私はあなたを助けるかもしれない非常に有用なプログラムを書いたと思います。 @Scovettaが述べたように、我々はPythonのin演算子を使うことができます。しかし、あなたがブルートフォース方法を使用し、Pythonの優れた構文的な砂糖を使用しないことに強く忠実であれば、間違いなくそれを行うことができます。

ここに私が書いたプログラム例があります。これが役に立ったら教えてください！ご質問があればお気軽にお問い合わせください。

# This program is just going to find if a string contains a substring 

def match(text, pattern): 
    ''' 
    Simple match program 
    ''' 
    if pattern in text: 
     return True 
    else: 
     return False 

test_cases = [['ab', 'bab'], ['cat', 'catdog'], ['banana', 'apple'], ['tree', 'tree']] 

def brute_match(text,pattern): 
    ''' 
    We just want to check that our text has our pattern 
    So let's just iterate over our text 
    ''' 
    length_of_pattern = len(pattern) 
    for i in range(len(text)): 
     # Abuse python's splicing because we don't have to worry about end of the string nonsense 
     if text[i:length_of_pattern+i] == pattern: 
      return True 
    return False 


for case in test_cases: 
    ans = match(case[1], case[0]) 
    bans = brute_match(case[1], case[0]) 
    print("{} is in {} (T/F): {}".format(case[0], case[1], ans)) 
    print("{} is in {} (T/F): {}".format(case[0], case[1], bans)) 


# Enter your main program 
# We want to loop infinitely unless we get qqq 
while True: 
    text_string = raw_input("Please enter your text string: ") 
    if text_string == 'qqq': 
     break 
    pattern_string = raw_input("Please enter your pattern string: ") 
    print("Using 'in' operator:") 
    print('-'*20) 
    if match(text_string): 
     print("IS a valid match") 
    else: 
     print("NOT a valid match") 
    print("Using brute force:") 
    print('-'*20) 
    if brute_match(text_string): 
     print("IS a valid match") 
    else: 
     print("NOT a valid match") 

コードがちょっと面倒だとわかりましたが、私はちょうどすぐにそれを書きたいと思っていました！

質問がある場合はお知らせください。