超越long long范围加法，包AC

超越long long范围加法

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

string addBigNumbers(const string& num1, const string& num2) {
    string result;
    int carry = 0, i = num1.size() - 1, j = num2.size() - 1;
    
    while (i >= 0 || j >= 0 || carry) {
        int sum = carry;
        if (i >= 0) sum += num1[i--] - '0';
        if (j >= 0) sum += num2[j--] - '0';
        result += (sum % 10) + '0';
        carry = sum / 10;
    }
    reverse(result.begin(), result.end());
    return result;
}

int main() {
    string num1, num2;
    cin >> num1 >> num2;
    cout << addBigNumbers(num1, num2);
    return 0;
}

测试：
输入
1234567891234567891234567891234567890
1234567891234567891234567891234567890
输出
2469135782469135782469135782469135780