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？