题解 | #正则表达式匹配#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param str string字符串 
# @param pattern string字符串 
# @return bool布尔型
#
class Solution:
    def match(self , str_i: str, pattern: str) -> bool:
        # write code here
        j=len(pattern)-1
        i=len(str_i)-1
        k=0
        while j>=0:
            if pattern[j]=='*':
                k=0
                j-=1
                if pattern[j]=='.':
                    return True
                while pattern[j]==str_i[i]:
                    i-=1
                    k+=1
                    if i==-1:
                        return True
                j-=1
                continue
            if pattern[j]==str_i[i] or pattern[j]=='.':
                k=0
                j-=1
                i-=1
                continue
            if pattern[j-1]==str_i[i] and k:
                i-=1
                k-=1
                continue
            return False
        if j==-1 and i==-1:
            return True
        return False