package org.example;

public class AddStrings {

public String addStrings(String num1, String num2) {

int p = num1.length() - 1;

int q = num2.length() - 1;

int carry = 0;

StringBuilder result = new StringBuilder();

while (p >= 0 && q >= 0) {

int n1 = num1.charAt(p) - '0';

int n2 = num2.charAt(q) - '0';

int sum = (n1 + n2 + carry) % 10;

carry = (n1 + n2 + carry) / 10;

// result.insert(0, sum);

result.append(sum);

p--;

q--;

}

while (p >= 0) {

int n1 = num1.charAt(p) - '0';

int sum = (n1 + carry) % 10;

carry = (n1 + carry) / 10;

p--;

// result.insert(0, sum);

result.append(sum);

}

while (q >= 0) {

int n2 = num2.charAt(q) - '0';

int sum = (n2 + carry) % 10;

carry = (n2 + carry) / 10;

q--;

// result.insert(0, sum);

result.append(sum);

}

if (carry > 0) {

// result.insert(0, '1');

result.append('1');

}

return result.reverse().toString();

}

}