Add Binary

#include <iostream>
#include <string>
using namespace std;

class Solution {
public:
    string addBinary(string a, string b) {
        // Make both strings of equal length by prepending zeros
        if(a.size() > b.size())
            b = string(a.size() - b.size(), '0') + b;
        else if(a.size() != b.size())
            a = string(b.size() - a.size(), '0') + a;
        
        string result(a.size(), '0'); // Initialize result string with zeros
        bool carry = false; // Initialize carry to false
        
        for(int i = a.size() - 1; i >= 0; --i)
        {
            if((a[i] == '1' && b[i] == '0') || (a[i] == '0' && b[i] == '1'))
            {
                result[i] = carry ? '0' : '1';
            }
            else if(a[i] == '0' && b[i] == '0')
            {
                result[i] = carry ? '1' : '0';
                carry = false;
            }
            else if(a[i] == '1' && b[i] == '1')
            {
                result[i] = carry ? '1' : '0';
                carry = true;
            }
        }
        if(carry)
            result = '1' + result;
        
        return result;
    }
};

int main() {
    Solution sol;
    string a = "1010";
    string b = "1011";
    cout << sol.addBinary(a, b) << endl; // Output should be "10101"

    return 0;
}