青训营刷题 创意标题匹配 简单题

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问题描述

在广告平台中,为了给广告主一定的自由性和效率,允许广告主在创造标题的时候以通配符的方式进行创意提交。线上服务的时候,会根据用户的搜索词触发的 bidword 对创意中的通配符(通配符是用成对 {} 括起来的字符串,可以包含 0 个或者多个字符)进行替换,用来提升广告投放体验。例如:“{末日血战} 上线送 SSR 英雄,三天集齐无敌阵容!”,会被替换成“帝国时代游戏下载上线送 SSR 英雄,三天集齐无敌阵容!”。给定一个含有通配符的创意和n个标题,判断这句标题是否从该创意替换生成的。

测试样例

样例1:

输入:n = 4, template = "ad{xyz}cdc{y}f{x}e", titles = ["adcdcefdfeffe", "adcdcefdfeff", "dcdcefdfeffe", "adcdcfe"]
输出:"True,False,False,True"

样例2:

输入:n = 3, template = "a{bdc}efg", titles = ["abcdefg", "abefg", "efg"]
输出:"True,True,False"

样例3:

输入:n = 5, template = "{abc}xyz{def}", titles = ["xyzdef", "abcdef", "abxyzdef", "xyz", "abxyz"]
输出:"True,False,True,True,True"

思路

这里关键是需要将中括号里面的内容替换成.*,这样就符合正则表达式的形式,而这一步的替换恰好是正则表达式的匹配问题,即,将{.*?}替换成.*

我们可以使用python的re库

Return the string obtained by replacing the leftmost non-overlapping occurrences of pattern in string by the replacement repl. If the pattern isn’t found, string is returned unchanged. repl can be a string or a function; if it is a string, any backslash escapes in it are processed. That is, \n is converted to a single newline character, \r is converted to a carriage return, and so forth. Unknown escapes of ASCII letters are reserved for future use and treated as errors. Other unknown escapes such as & are left alone. Backreferences, such as \6, are replaced with the substring matched by group 6 in the pattern. For example:

>>> re.sub(r'def\s+([a-zA-Z_][a-zA-Z_0-9]*)\s*(\s*):',
...        r'static PyObject*\npy_\1(void)\n{',
...        'def myfunc():')
'static PyObject*\npy_myfunc(void)\n{'

If repl is a function, it is called for every non-overlapping occurrence of pattern. The function takes a single Match argument, and returns the replacement string. For example:

>>> def dashrepl(matchobj):
...     if matchobj.group(0) == '-': return ' '
...     else: return '-'
...
>>> re.sub('-{1,2}', dashrepl, 'pro----gram-files')
'pro--gram files'
>>> re.sub(r'\sAND\s', ' & ', 'Baked Beans And Spam', flags=re.IGNORECASE)
'Baked Beans & Spam'

Compile a regular expression pattern into a regular expression object, which can be used for matching using its match()search() and other methods, described below.

The expression’s behaviour can be modified by specifying a flags value. Values can be any of the flags variables, combined using bitwise OR (the | operator).

The sequence

prog = re.compile(pattern)
result = prog.match(string)

is equivalent to

result = re.match(pattern, string)

but using re.compile() and saving the resulting regular expression object for reuse is more efficient when the expression will be used several times in a single program.(由于我们这里要匹配一个list,所以我们先保存正则表达式,然后遍历list进行匹配)

  • re.match(patternstringflags=0)

If zero or more characters at the beginning of string match the regular expression pattern, return a corresponding Match. Return None if the string does not match the pattern; note that this is different from a zero-length match.

完整代码

import re

def solution(n, template_, titles):
    regex_pattern = re.sub(r'\{.*?\}', '.*', template_)
    pattern = re.compile(f'^{regex_pattern}$')
    
    results = []
    for title in titles:
        if pattern.match(title):
            results.append("True")
        else:
            results.append("False")
    
    return ",".join(results)

if __name__ == "__main__":
    #  You can add more test cases here
    testTitles1 = ["adcdcefdfeffe", "adcdcefdfeff", "dcdcefdfeffe", "adcdcfe"]
    testTitles2 = ["CLSomGhcQNvFuzENTAMLCqxBdj", "CLSomNvFuXTASzENTAMLCqxBdj", "CLSomFuXTASzExBdj", "CLSoQNvFuMLCqxBdj", "SovFuXTASzENTAMLCq", "mGhcQNvFuXTASzENTAMLCqx"]
    testTitles3 = ["abcdefg", "abefg", "efg"]

    print(solution(4, "ad{xyz}cdc{y}f{x}e", testTitles1) == "True,False,False,True" )
    print(solution(6, "{xxx}h{cQ}N{vF}u{XTA}S{NTA}MLCq{yyy}", testTitles2) == "False,False,False,False,False,True" )
    print(solution(3, "a{bdc}efg", testTitles3) == "True,True,False" )