G面经prepare: Pattern Match

设定一个pattern 把 'internationalization' 变成 'i18n', 比如word是house，pattern可以是h3e, 3se, 5, 1o1s1等，
给pattern和word，判断是否match，

 package DataStreamAverage;

 public class Solution3 {
     public boolean check(String s1, String s2) {
         return helper(s1, 0, s2, 0);
     }

     public boolean helper(String s1, int i1, String s2, int i2) {
         if (i1==s1.length() && i2==s2.length()) return true;
         if (i1==s1.length() || i2==s2.length()) return false;
         if (isDigit(s2.charAt(i2))) {
             int num = 0;
             while (i2<s2.length() && isDigit(s2.charAt(i2))) {
                 num = num*10 + (int)(s2.charAt(i2)-'0');
                 i2++;
             }
             if (i1+num > s1.length()) return false;
             return helper(s1, i1+num, s2, i2);
         }
         else {
             if (s1.charAt(i1) != s2.charAt(i2)) return false;
             return helper(s1, i1+1, s2, i2+1);
         }
     }

     public boolean isDigit(char c) {
         if (c>='0' && c<='9') return true;
         else return false;
     }

     /**
      * @param args
      */
     public static void main(String[] args) {
         // TODO Auto-generated method stub
         Solution3 sol = new Solution3();
         boolean res = sol.check("houskjfjjdkse", "h11e");
         if (res) System.out.println("True");
         else System.out.println("false");
     }

 }