大數相加問題

</pre><pre name="code" class="cpp">#include "stdafx.h"
#include <string>
#include <iostream>

using namespace std;

int main() {
	string s1, s2, ss1 , ss2;
	cin >> s1 >> s2;

    int  n = s1.size();            //逆置字符串
	int  m = s2.size();
	for (int  i = 0; i < n; i++)
	{
		ss1 = s1[i] + ss1;
	}
	for (int i = 0; i < m; i++)
	{
		ss2 = s2[i] + ss2;
	}
	                            
	if (n > m)                    //補齊位數
	{
		for (int i = 0; i < n-m; i++)
		{
			ss2 = ss2 + "0";
		}
	}
	else {
		for (int i = 0; i < m-n; i++)
		{
			ss1 = ss1 + "0";
		}
	}
	
	int add, mid = 0;           //模擬計算
	string sum, min;
	int r = n > m ? n : m;
	for (int i = 0; i < r; i++)
	{
		add = mid + ss1[i] - '0' + ss2[i] - '0';
		if (add >= 10)
		{
			mid = 1;
			add = add - 10;
			min = add + '0';
			sum = min + sum;
		}
		else {
			min = add + '0';
			sum = min + sum;
			mid = 0;
		}
	}
	if (mid == 1)          //判斷最後一位爲10以上的情況
	{
		sum = "1" + sum;
	}
	cout << sum << endl;
}