C++实现——大数相加

#include <iostream>#include <string>using namespace std;//大数相加/***num1 加数1*num2 加数2*res  返回值*///处理函数void bigAdd(string num1, string num2, string&res){    if (num1.size() == 0){        res = num2;        return;    }    if (num2.size() == 0){        res = num1;        return;    }    res = "";    int n1 = num1.size()-1, n2 = num2.size()-1;    int carry = 0;    while (n1 >= 0 || n2 >= 0){        int a = n1 >= 0 ? num1[n1--] - '0' : 0;        int b = n2 >= 0 ? num2[n2--] - '0' : 0;        int t = carry + a + b;        carry = t / 10;        t = t % 10;        res = to_string(t) + res;    }    //判断是否还有进位    while (carry){        int t = carry / 10;        carry %= 10;        res = to_string(carry) + res;        carry = t;    }    return;}//测试函数int main(){    string n1, n2, n3;    while (cin >> n1 >> n2){        bigAdd(n1,n2,n3);        cout << n3 << endl;    }    return 0;}