每天30道四则运算题目（随机数习题）

代码如下：

include

int main()
{
srand(static_cast(time(nullptr)));

for (int i = 0;i < 30;i++)
{
	int num1 = rand() % 100;
	int num2 = rand() % 100;
	int Sw = rand() % 4;
	cout << "第" << i+1 << "题：";
	switch (Sw)
	{
	case 1:
	{
		cout << num1 << "+" << num2 << "=" << "\t";
		cout << "正确答案：" << num1 + num2 << endl;
		break;
	}
	case 2:
	{
		cout << num1 << "-" << num2 << "=" << "\t";
		cout << "正确答案：" << num1 - num2 << endl;
		break;
	}
	case 3:
	{
		cout << num1 << "*" << num2 << "=" << "\t";
		cout << "正确答案：" << num1 * num2 << endl;
		break;
	}
	case 4:
	{
		cout << num1 << "/" << num2 << "=" << "\t";
		cout << "正确答案：" << num1 / num2 << endl;
		break;
	}
	default:
	{
		cout << num1 << "+" << num2 << "=" << "\t";
		cout << "正确答案：" << num1 + num2 << endl;
		break;
	}
	}
}
return 0;

}

难点：
1.用了随机数种子srand(static_cast(time(nullptr)))来利用时间生成随机数，这样每一次再使用rand函数的时候获得的就是不一样的随机数
2.在四则运算随机生成地时候，用第二个随机数种子生成从0-4的随机数，来代表四则运算要用哪个