LeetCode10.正则表达式匹配（java）

public static boolean isMatch(String s, String p) {

        char[] schar = s.toCharArray();
        char[] pchar = p.toCharArray();
        int slength = s.length();
        int plength = p.length();
        boolean[][] dp = new boolean[slength + 1][plength + 1];
        
        dp[0][0] = true;
        
        for (int j = 1; j < plength + 1; j++) {
            if (pchar[j - 1] == '*') {
                dp[0][j] = dp[0][j - 2];
            }
        }
        
        for (int i = 1; i < slength + 1; i++) {
            for (int j = 1; j < plength + 1; j++) {
                
                if (pchar[j - 1] == '.') {
                    dp[i][j] = dp[i - 1][j - 1];
                }
                
                else if (pchar[j - 1] == '*') {
                    
                    if (pchar[j - 2] == '.') {
                        if (dp[i][j - 2] || dp[i][j - 1] || dp[i - 1][j])
                            dp[i][j] = true;
                    }
                    
                    else {
                        if (dp[i][j - 2] || dp[i][j - 1] || (schar[i - 1] == pchar[j - 2] 
                            && dp[i - 1][j]))
                            dp[i][j] = true;
                    }
                }
                
                else {
                    if (schar[i - 1] == pchar[j - 1])
                        dp[i][j] = dp[i - 1][j - 1];
                }
            }
        }
        return dp[slength][plength];
}