为啥第二个测试集我的输出是对的还是WA？有没有大佬看看我的问题在哪？

源码如下：

#include<iostream>
#include<vector>
#include<algorithm>
#include<string>
using namespace std;
bool hui(vector<int>);
bool hui(vector<int>a)
{
    vector<int> s = a;
    reverse(s.begin(), s.end());
    return s == a;
}
void jia(vector<int>&, int);
void jia(vector<int>& a, int n)
{
    vector<int>d = a;
    reverse(d.begin(), d.end());
    int b = 0;
    for (int i = 0; i < a.size(); i++)
    {
        a[i] = a[i] + d[i] + b;
        if (a[i] >= n)
        {
            b = a[i] / n;
            a[i] %= n;
        }
        else
            b = 0;
    }
    if (b)
    {
        a.push_back(b);
        b = 0;
    }
}
bool hui(string);
bool hui(string a)
{
    string s = a;
    reverse(s.begin(), s.end());
    return a == s;
}
int main()
{
    int n, m,s=0;
    cin >> n;
    if (n < 16)
    {
        cin >> m;
        vector<int>a;
        int b = m % 10, c = m / 10;
        while (c != 0)
        {
            a.push_back(b);
            b = c % 10, c /= 10;
        }
        a.push_back(b);
        if (hui(a))
        {
            cout << "STEP=" << s; return 0;
        }
        while (!hui(a))
        {
            jia(a, n);
            s++;
            if (s > 30)
                break;
        }
        if (s > 30)
        {
            cout << "Impossible!";
        }
        else
            cout << "STEP=" << s;
    }
    else
    {
        cin.get();
        string a;
        getline(cin, a);
        int f = 0;
        if (hui(a))
        {
            cout << "STEP=" << "0";
        }
        else
        {
            vector<int>r;
            for (int i = 0; i < a.size(); i++)
            {
                if (int(a[i] > 64))
                {
                    r.push_back(int(a[i]) - 55);
                }
                else
                {
                    r.push_back(int(a[i]) - 48);
                }
            }
            while (!hui(r))
            {
                jia(r, 16);
                f++;
                if (f > 30)
                    break;
            }
            if (f > 30)
            {
                cout << "Impossible!";
            }
            else
                cout << "STEP=" << f;
        }
    }
}

输入：16\nAC27 我在Windows10的VS2019上测出来的结果是：“STEP=6”，在洛谷上就是不对！我应该没用linux的关键词吧？