String Matcher Algorithm - Naive

naive_string_matcher.py

"""
November 9th, 2021

Naive Implmementation

Exacution example
> python3 string_match.py
"""
class StringMatch():
    text: str
    pattern: str

    def __init__(self, text: str, pattern: str):
        self.text = text
        self.pattern = pattern


def naive_string_matcher(text: str, pattern: str) -> int:
    n, m = len(text), len(pattern)

    for s in range(0, n - m):
        if pattern[1:m] == text[s+1:s+m]:
            return s


if __name__ == '__main__':
    print('[START] Naive String Matcher\n')
    tests = [
        StringMatch('fresh fried fish', 'sh'),
        StringMatch('honda civic ek9', 'ek')
    ]

    for stringMatchCase in tests:
        out = naive_string_matcher(stringMatchCase.text, stringMatchCase.pattern)
        print(f'Text: "{stringMatchCase.text}"')
        print(f'Pattern: "{stringMatchCase.pattern}"')
        print(f'El patrón ocurre con desplazamiento: {out}\n')

    print('[END] Naive String Matcher')

Execution output:

[START] Naive String Matcher

Text: "fresh fried fish"
Pattern: "sh"
El patrón ocurre con desplazamiento: 3

Text: "honda civic ek9"
Pattern: "ek"
El patrón ocurre con desplazamiento: 12

[END] Naive String Matcher