HDU ACM 11 2031 进制转换

#include <iostream>
using namespace std;
int main()
{
	int n, r, i = 0;
	char Lu[100];
	while (cin >> n >> r)
	{
		if (n < 0)
		{
			cout << "-";
			n = -n;
		}
		while (n > 0)
		{
			int Yi = n%r;
			if (Yi > 9)
				Lu[i] = Yi - 10 + 'A';
			else
				Lu[i] = Yi + '0';
			i++;
			n = n/r;
		}
		int j = i;
		while (j--)
			cout << Lu[j];
		cout << endl;
		i = 0;
	}
	return 0;
}