进制转换器

oct→八进制
dec→十进制
hex→16进制

int main() {
	cout << "BHD Converter\n";
	cout << "1.Decimal to octal or hexadecimal\n";
	cout << "2.Octal to decimal or hexadecimal\n";
	cout << "3.Hexadecimal to octal or decimal\n";
	int choose{};
	int num{};
	cout << "select the conversion you need:";
	cin >> choose;
	switch (choose)
	{
	case 1:
		cout << "Enter a decimal number:";
		cin >> num;
		cout << oct;//修改cout显示整数的方式
		cout << "octal is " << num << endl;
		cout << hex;//同上
		cout << "hexadecimal is " << num;
		break;
	case 2:
		cout << "Enter a octal number:";
		cin >> oct;//修改输入整数的方式
		cin >> num;
		cout << "decimal is " << num << endl;
		cout << hex;
		cout << "hexadecimal is " << num;
		break;
	case 3:
		cout << "Enter a hexadecimal number:";
		cin >> hex;
		cin >> num;
		cout << oct;
		cout << "octal is " << num << endl;
		cout << dec;
		cout << "decimal is " << num;
		break;
	default:
		break;
	}
	system("pause");
	return 0;
}