← Recursion & DP

Micro-Drill #179 — Wildcard Matching

Recursion & DP Target: 15s

'*' matches any sequence (dp[i-1][j] = consume char, dp[i][j-1] = empty match). '?' matches any single char.

def isMatch(s, p):
    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-1]
    for i in range(1, m+1):
        for j in range(1, n+1):
            if p[j-1] == '*':
                dp[i][j] = dp[i-1][j] or dp[i][j-1]
            elif p[j-1] == '?' or p[j-1] == s[i-1]:
                dp[i][j] = dp[i-1][j-1]
    return dp[m][n]

Type it from memory. Go.

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