高精加法

屈老师

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

string addBigNumbers(string a, string b) {
    // 确保 a 是较长的字符串
    if (a.length() < b.length()) {
        swap(a, b);
    }

    string result = "";
    int carry = 0;

    // 反转方便从低位开始加
    reverse(a.begin(), a.end());
    reverse(b.begin(), b.end());

    for (size_t i = 0; i < a.length(); ++i) {
        int digitA = a[i] - '0';
        int digitB = (i < b.length()) ? b[i] - '0' : 0;
        int sum = digitA + digitB + carry;
        result += (sum % 10) + '0';
        carry = sum / 10;
    }

    if (carry) {
        result += carry + '0';
    }

    // 结果反转回正常顺序
    reverse(result.begin(), result.end());
    return result;
}

int main() {
    string num1, num2;
    cout << "请输入两个大整数：" << endl;
    cin >> num1 >> num2;

    string sum = addBigNumbers(num1, num2);
    cout << "和为：" << sum << endl;
    return 0;
}