[数据结构与算法]C语言程序设计苏小红课后习题答案7.14.4

//生成随机符号
char Charop()
{
	int op;
	op = rand() % 4 + 1;
	switch (op)
	{
	case 1:return '+';
	case 2:return '-';
	case 3:return '*';
	case 4:return '/';
	}
	return 0;
}
//相关计算
int Calculate(int x, char op, int y)
{
	int a, b, c, d;
	a = x + y;
	b = x - y;
	c = x * y;
	d = x / y;
	switch (op)
	{
	case '+': return a;
	case '-': return b;
	case '*': return c;
	case '/': return d;
	default:return 0;
	}
}
//输出运算
int fun()
{
	int answer, counter = 0, grade = 0;
	int x, y, m, n;
	char op;
	for (int i = 1;i <= 10;i++)
	{
		op = Charop();
		srand(time(NULL));
		x = rand() % 10 + 1;
		y = rand() % 10 + 1;
		printf("%d%c%d=", x, op, y);
		scanf("%d", &answer);
		if (answer == Calculate(x, op, y))
		{
			printf("Right!\n");
			grade++;
		}
		else
			printf("Wrong!\n");
		counter++;
	}
	printf("grade=%d\n", grade);
	printf("Scoring rate=%d%%", grade * 10);
}
//主函数
int main()
{
	fun();
	return 0;
}