1 public class Solution {
2 public String addBinary(String a, String b) {
3 int len1 = a.length();
4 int len2 = b.length();
5 StringBuilder sb = new StringBuilder();
6 int p1 = len1-1;
7 int p2 = len2 -1;
8 int carry = 0;
9 while(p1>=0&&p2>=0){
10 int temp = a.charAt(p1)-'0'+b.charAt(p2)-'0'+carry;
11 carry = temp/2;
12 sb.append(temp%2);
13 p1--;p2--;
14 }
15 while(p1>=0){
16 int temp = a.charAt(p1)-'0'+carry;
17 carry = temp/2;
18 sb.append(temp%2);
19 p1--;
20 }
21 while(p2>=0){
22 int temp = b.charAt(p2)-'0'+carry;
23 carry = temp/2;
24 sb.append(temp%2);
25 p2--;
26 }
27 if(carry>0)
28 sb.append(carry);
29 return sb.reverse().toString();
30 }
31 }
