power_of_two.cpp

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#include <iostream>  
#include <cassert>   
 
 
namespace math {
int power_of_two(int n) {
    int result = n & (n - 1);
    
    if (result == 0) {
        return 1;
    }
 
    return 0;
}
}  // namespace math
 
static void test() {
    std::cout << "First case testing... \n"; // for n = 32 return 1
    assert(math::power_of_two(32) == 1);
    std::cout << "\nPassed!\n";
 
    std::cout << "Second case testing... \n"; // for n = 5 return 0
    assert(math::power_of_two(5) == 0);
    std::cout << "\nPassed!\n";
 
    std::cout << "Third case testing... \n"; // for n = 232 return 0
    assert(math::power_of_two(232) == 0);
    std::cout << "\nPassed!\n";
 
    std::cout << "\nAll test cases have successfully passed!\n";
}
 
void user_input_test() {
    int n = 0; // input from user
    
    std::cout << "Enter a number " << std::endl;
    std::cin >> n; 
 
    int result = math::power_of_two(n);
    if (result == 1) {
        std::cout << "Yes, the number " << n << " is a power of 2\n";
    }
    else { 
        std::cout << "No, the number " << n << " is not a power of 2\n";
    }
}
 
int main() {
    test(); // run self-test implementations
 
    // uncomment the line below to take user inputs
    //user_input_test();
 
    return 0;
}