求救！！！

#include <bits/stdc++.h>
using namespace std;
int n, x, num;
string s, s1 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", ans;
inline int jin(string s, int n)
{
	int num, ans(0);
	for (int i(0); i <= s.size() - 1; i++)
	{
		if (s[i] >= 65) num = int(s[i]) - 55;
		else num = int(s[i]) - 48;
		ans += num * pow(n, s.size() - i - 1);
	}
	return ans;
}
inline string zhi(int n, int x)
{
	string ans = "";
	while (n)
	{
		ans += s1[n % x];
		n /= x;
	}
	reverse(ans.begin(), ans.end());
	return ans; 
}
int main()
{
    cin >> n >> s >> x;
    num = jin(s, n);
    ans = zhi(num, x);
    return 0;
}

PS.玄一关