Regular Expression Matching

Implement regular expression matching with support for '.' and '*'.

'.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial). The function prototype should be: bool isMatch(const char *s, const char *p) Some examples: isMatch("aa","a") → false isMatch("aa","aa") → true isMatch("aaa","aa") → false isMatch("aa", "a*") → true isMatch("aa", ".*") → true isMatch("ab", ".*") → true isMatch("aab", "c*a*b") → true

class  Solution {
public:
     bool isMatch( const  char *s,  const  char *p) 
    {
         int lens=strlen(s);
         int lenp=strlen(p);
         bool* check= new  bool[lens+ 1];
        check[ 0]= true;
         for( int j= 1;j<=lens;j++)
            check[j]= false;

         for( int i= 0;i<lenp;i++)
        {
             if(p[i]!= ' * ' && p[i+ 1]!= ' * ' && p[i]!= ' . ')
            {
                 for( int j=lens;j>= 0;j--)
                    check[j]=check[j- 1] && (p[i]==s[j- 1]);                
            }
             if(p[i]== ' . ' && p[i+ 1]!= ' * ')
            {
                 for( int j=lens;j>= 0;j--)
                    check[j]=check[j- 1];                
            }
             if(p[i+ 1]== ' * ')
            {
                 char c=p[i];                
                 if(c== ' * ')
                     for( int j= 1;j<=lens;j++)
                        check[j]= true;
                 else  if(c== ' . ')
                {
                     // find the first match
                     int j= 0;
                     while(check[j]== false && j<=lens) j++;
                     // then all the next match 
                     if(j<=lens)
                         for(;j<=lens;j++)
                            check[j]= true;
                }
                 else     for( int j= 1;j<=lens;j++)
                         if(check[j- 1] && c==s[j- 1])
                            check[j]= true;
                i++;
            }    
            check[ 0]=check[ 0] && (p[i]== ' * ');
        }
         return check[lens];
    }
};