Simple and Easy to understand in C++

#1

string Solution::addBinary(string A, string B) {
reverse(A.begin(),A.end());
reverse(B.begin(),B.end());

if(A.size()<B.size()) {
    while(A.size()!=B.size()) A.push_back('0');
}
else while(A.size()!=B.size()) B.push_back('0');

int m=A.size();
if(m==0) return B;

string res;
int carry=0,i=0;
while(i<m || carry)
    {
        int val=0;
        if(i<m) val=A[i]-'0'+B[i]-'0';
        val+=carry;
        carry=val/2;
        res.push_back(val%2+'0');
        i++;
    }

while(res.size()>1 && res[res.size()-1]=='0') res.pop_back();

reverse(res.begin(),res.end());

return res;

}