题解 | 高精度整数加法

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

int main() {
    string num1,num2;
    cin>>num1>>num2;

   // 确保num1是较长的数字
    if (num1.length() < num2.length())
        swap(num1, num2);
    
    string result = "";
    int carry = 0;
    int diff = num1.length() - num2.length();
    
    // 从右向左加每一位数字
    for (int i = num1.length() - 1; i >= 0; i--) {
        int sum = (num1[i] - '0');
        if (i - diff >= 0)
            sum += (num2[i - diff] - '0');
        sum += carry;
        
        carry = sum / 10;
        result.push_back(sum % 10 + '0');
    }
    
    // 如果存在剩余进位，添加进位
    if (carry)
        result.push_back(carry + '0');
    
    // 反转结果
    reverse(result.begin(), result.end());
    

    cout<<result;
    return 0;
}
// 64 位输出请用 printf("%lld")