下面程序的输出为：
int main() {
int N = 15, cnt = 0;
for (int x = 0; x + x + x <= N; x++)
for (int y = x; x + y + y <= N; y++)
for (int z = y; x + y + z <= N; z++)
cnt++;
cout << cnt << endl;
return 0;
}
- A. 174
- B. 447
- C. 816
- D. 4096
正确答案：A