51nod 1069 Nim游戏

#include <iostream>

const int MAX = 1e3 + 5;
int arr[MAX];

int main()
{
int num;
std::cin >> num;
for (int i = 1; i <= num; ++i)
{
if(i == 1)
{
std::cin >> arr[i];
continue;
}
else
{
std::cin >> arr[i];
arr[1] = (arr[1] ^ arr[i]);
}
}
if (arr[1])
std::cout << "A\n";
else
std::cout << "B\n";

return 0;
}