Add Binary

code

class Solution {
public:
    string addBinary(string a, string b) {
        string ret;
        reverse(a.begin(), a.end());
        reverse(b.begin(), b.end());
        string ar = a;
        string br = b;

        int i = 0;
        int j = 0;
        int carry = 0;
        while(i < ar.length() && j < br.length())
        {
            int res = int(ar[i]) - '0' + int(br[j]) - '0' + carry;
            carry = res/2;
            res = res%2;
            ret += to_string(res);
            i++;
            j++;
        }

        while(i < ar.length())
        {
            int res = int(ar[i]) - '0' + carry;
            carry = res/2;
            res = res%2;
            ret += to_string(res);
            i++;
        }

        while(j < br.length())
        {
            int res = int(br[j]) - '0' + carry;
            carry = res/2;
            res = res%2;
            ret += to_string(res);
            j++;
        }

        if(carry == 1)
        {
            ret += "1";
        }
        reverse(ret.begin(), ret.end());
        return ret;
    }
};

```

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