Given two binary strings, return their sum (also a binary string).

For example,

a = "11"

b = "1"

Return "100".

1 import java.util.Stack; 2  3  4 public class Solution { 5     public static String addBinary(String a, String b) { 6     Stack
     
       st=new Stack(); 7     int lena=a.length();int lenb=b.length(); 8     String comp=""; 9     for(int i=0;i
      
       =0;i--){15         char x=a.charAt(i);char y=b.charAt(i);16         int res=x-'0'+y-'0'+jin;17         if(res>=2){jin=1;res-=2;}18         else{jin=0;}19         st.add(res);20     }21     if(jin==1){st.add(jin);}22     String t="";23     while(!st.isEmpty()){24         t+=st.pop();25     }26     return t;27     }28     public static void main(String[]args){29     System.out.println(addBinary("110","11"));30     }31 }