请问有啥错误没有呀，孩子改不动了。。。 代码如下：

#include<iostream>
using namespace std;
int main()
{
	string k, m;
	cin >> k >> m;
	int j;
	for (int i = 0; i < m.length(); i++)
	{
		if ((i + 1) <= k.length())
			j = i;
		else j = i % k.length();
		//int t = ((k[j] >= 'A' && k[j] <= 'Z') ? k[j] - 'A' : k[j] - 'a');
		int t=0; 
		if (k[j] >= 'A' && k[j] <= 'Z')
			t = k[j] - 'A';
		else if (k[j] >= 'a' && k[j] <= 'z')
			t = k[j] - 'a';
		if ((m[i] >= 'a' && m[i] <= 'z' && m[i] + t > 'z') || (m[i] >= 'A' && m[i] <= 'Z'&&m[i] + t > 'Z'  ))
			m[i] = m[i] + t - 26;
		else m[i] += t;
	}
	cout << m << endl;
	return 0;
}