C++ :

#include <iostream>
using namespace std;

// 函数: 判断一个整数是否为2的幂
bool isPowerOfTwo(int n) {
    return (n > 0) && (n & (n - 1)) == 0;
}

int main() {
    int n;
    cin >> n; // 读取输入
    if (isPowerOfTwo(n)) {
        cout << n << " is a power of two." << endl; 
    } else {
        cout << n << " is not a power of two." << endl;
    }
    return 0;
}