Regular expression Matching,regex, regex matching, using dynamic programming

//Dynamic Planning Public classRegex { Public BooleanIsMatch (String s, String p) {//p length is 0, boundary condition.         if(p.length () = = 0) {            returnS.length () = = 0; }             //p length is 1, boundary condition.         if(p.length () = = 1) {                 //s length is 0            if(S.length () < 1) {                return false; }            //There are two cases of first element matching//if P is. Then s the first element and P must match, and if the first element of P is the same as the first element of S, it must also match.             Else if((P.charat (0)! = S.charat (0)) && (P.charat (0)! = '. ')) {                return false; }                 //otherwise, in addition to the first matching element, compare other elements to the idea of dynamic planning.             Else {                returnIsMatch (s.substring (1), p.substring (1)); }        }             //the second element of P is not a *,* representing 0 or more preceding elements        if(P.charat (1)! = ' * ')        {            if(S.length () < 1)             {                return false; }            Else if((P.charat (0)! = S.charat (0)) && (P.charat (0)! = '. '))            {                return false; }             Else             {                returnIsMatch (s.substring (1), p.substring (1)); }        }             Else  //the second element of P is *        {            //* represents 0 elements in front of each other            if(IsMatch (S, p.substring (2)))             {                return true; }                 //* represents one or more of the preceding elements            inti = 0;  while(I<s.length () && (S.charat (i) ==p.charat (0) | | P.charat (0) = = '. '))            {                if(IsMatch (s.substring (i + 1), p.substring (2)))                {                    return true; } I++; }            return false; }    }     Public Static voidMain (string[] args) {Regex2 reg2=NewRegex2 (); System.out.println (Reg2.ismatch ("Aaba", "Ab*a*c*a")); }}

Regular expression Matching,regex, regex matching, using dynamic programming