Regular Expression Matching
Given an input string s and a pattern p, implement regular expression matching with support for '.' and '*' where:
'.' Matches any single character.
'*' Matches zero or more of the preceding element.
The matching should cover the entire input string (not partial).
class Solution:
def isMatch(self, s: str, p: str) -> bool:
m, n = len(s), len(p)
dp = [[False] * (n+1) for _ in range(m+1)]
dp[0][0] = True
for j in range(1, n+1):
if p[j-1] == '*':
dp[0][j] = dp[0][j-2]
else:
dp[0][j] = j > 1 and p[j-2] == '*' and dp[0][j-2]
for i in range(1, m+1):
for j in range(1, n+1):
if p[j-1] == s[i-1] or p[j-1] == '.':
dp[i][j] = dp[i-1][j-1]
elif p[j-1] == '*':
dp[i][j] = dp[i][j-2] or (p[j-2] == s[i-1] or p[j-2] == '.') and dp[i-1][j]
else:
dp[i][j] = False
return dp[m][n]Related Problems
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