struct Solution {}

impl Solution {
    pub fn add_binary(a: String, b: String) -> String {
        let mut result = String::new();
        let mut carry = 0;

        // Convert strings to character vectors and reverse them for easier processing
        let a_chars: Vec<char> = a.chars().rev().collect();
        let b_chars: Vec<char> = b.chars().rev().collect();

        // Get the maximum length of the two strings
        let max_len = std::cmp::max(a_chars.len(), b_chars.len());

        // Perform binary addition digit by digit
        for i in 0..max_len {
            // Get digits at current position or 0 if we've reached the end
            let a_digit = if i < a_chars.len() {
                a_chars[i].to_digit(2).unwrap()
            } else {
                0
            };
            let b_digit = if i < b_chars.len() {
                b_chars[i].to_digit(2).unwrap()
            } else {
                0
            };

            // Calculate sum and new carry
            let sum = a_digit + b_digit + carry;
            carry = sum / 2;
            let digit = sum % 2;

            // Add the current digit to the result
            result.push(char::from_digit(digit, 2).unwrap());
        }

        // Don't forget the final carry if it exists
        if carry > 0 {
            result.push('1');
        }

        // Reverse the result and return
        result.chars().rev().collect()
    }

    // pub fn add_binary(a: String, b: String) -> String {
    //     let num1 = u128::from_str_radix(a.as_str(), 2).expect("Valid binary string");
    //     let num2 = u128::from_str_radix(b.as_str(), 2).expect("Valid binary string");

    //     let sum = num1 + num2;

    //     let binary_sum = format!("{:b}", sum); // format as binary string

    //     println!("Sum in decimal: {}", sum);
    //     println!("Sum in binary: {}", binary_sum);
    //     binary_sum
    // }
}

fn main() {
    let a: String = "111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111".to_string();
    let b: String = "11010100101110111000111".to_string();

    println!("{:?}", Solution::add_binary(a, b));
}