C++ 素数判断代码示例

/***************** Start ****************/ #include using namespace std;

bool isPrime(int num) { if(num < 2) { return false; } for(int i = 2; i <= num/2; i++) { if(num % i == 0) { return false; } } return true; }

int main(){ int num; cout << 'Enter a number: '; cin >> num;

if(isPrime(num)) {
    cout << num << ' is a prime number.' << endl;
} else {
    cout << num << ' is not a prime number.' << endl;
}

return 0; 

} /***************** End ****************/