题解 | #高精度整数加法#

#include <iostream>
#include <string>
#include <algorithm> // 包含 std::reverse

using namespace std;

string add_two_string(const string& a, const string& b) {
    string result; // 存储最终结果
    int carry = 0; // 进位标志

    // 逆转字符串方便计算
    string rev_a = a;
    string rev_b = b;
    reverse(rev_a.begin(), rev_a.end());
    reverse(rev_b.begin(), rev_b.end());

    int max_len = max(rev_a.size(), rev_b.size());

    for (int i = 0; i < max_len || carry; ++i) {
        int digit_a = (i < rev_a.size()) ? rev_a[i] - '0' : 0;
        int digit_b = (i < rev_b.size()) ? rev_b[i] - '0' : 0;

        int sum = digit_a + digit_b + carry;
        carry = sum / 10;
        result.push_back((sum % 10) + '0');
    }

    // 逆转结果字符串
    reverse(result.begin(), result.end());
    return result;
}

int main() {
    string a, b;
    cin >> a >> b;
    string result = add_two_string(a, b);
    cout << result << endl;
    return 0;
}