#include <bits/stdc++.h>
using namespace std;
int a[10005], tot;
inline int read()
{
	int s = 0, w = 1;char ch = getchar();
	while(ch < '0' || ch > '9'){if(ch == '-') w = -1;ch = getchar();}
	while(ch >= '0' && ch <= '9'){s = s * 10 + ch - '0';ch = getchar();}
	return s * w;
}
string s;
int b[10005], n;
inline void C(int n, int m)
{
	int sum = 0, y;
	while(n)
	{
		y = n % m;
		a[++ tot] = y;
		n /= m;
	}
	return ;
}
inline int B()
{
	int sum = 0;
	for(int i = s.size() - 1;i >= 0;i --)
	{
		sum += pow(b[i], s.size() - i - 1);
	}
	return sum;
}
int main()
{
	n = read();int m;
	cin >> s;
	for(int i = 0;i < s.size();i ++)
	if(s[i] >= '0' && s[i] <= '9') b[i] = s[i] - '0';
	else
	{
		if(s[i] == 'A') b[i] = 10;
		if(s[i] == 'B') b[i] = 11;
		if(s[i] == 'C') b[i] = 12;
		if(s[i] == 'D') b[i] = 13;
		if(s[i] == 'E') b[i] = 14;
		if(s[i] == 'F') b[i] = 15;
	}
	m = read();
	bool flag = false;
	C(B(), m);
	for(int i = tot;i >= 1;i --)
	{
		cout << a[i];
	}
	return 0;
}

这怎么搞一直错误

题目：https://www.luogu.com.cn/problem/T258192

求求各位大佬看看吧（啊啊啊啊啊）