C语言寒假大作战03

问题	答案
这个作业属于哪个课程	https://edu.cnblogs.com/campus/zswxy/CST2019-4/homework/10269
这个作业要求在哪	https://edu.cnblogs.com/campus/zswxy/CST2019-4/homework/10269
这个作业的目标	运用rand()函数
作业正文	https://i.cnblogs.com/posts/edit;postId=12297716
其他参考文献	百度 csdn https://www.runoob.com/cprogramming/c-function-rand.html

2.2.2设计思路和遇到的问题

设计思路：

在上次作业的基础上运用rand函数。

2.2.3 程序结果截图

2.2.4 程序代码

#include <stdio.h>
#include<stdlib.h>
#include<time.h> 
void menu();
void help();
void error();
void operation_1();
void one_1();
void operation_2();
void two_1();
void operation_3();
void three_1();
int main()
{
	int n;
	printf("========== 口算生成器 ==========
");
	printf("欢迎使用口算生成器 ：
");
	printf("小学生必备神器
");
	printf("
");
	help();
	while (1)
	{
		menu();
		scanf_s("%d", &n);
		switch (n)
		{
		case 1:operation_1(); break;
		case 2:operation_2(); break;
		case 3:operation_3(); break;
		case 4:help(); break;
		}
		printf("
");
		if (n == 5) break;
		if (n > 5 || n < 1) error();
	}
	return 0;
}
void help()
{
	printf("帮助信息
");
	printf("您需要输入命令代号来进行操作
");
	printf("一年级题目为不超过十位的加减法
");
	printf("二年级题目为不超过百位的乘除法
");
	printf("三年级题目为不超过百位的加减乘除混合题目
");
	printf("
");
}
void menu()
{
	printf("操作列表:
1)一年级    2)二年级    3)三年级
");
	printf("4)帮助      5)退出程序
请输入代号:");
}
void error()
{
	printf("哦买噶 错啦 请重新输入 ");
	printf("
");
	printf("
");
}
void operation_1()
{
	printf("请输入题目数量>");
	one_1();
}
void operation_2()
{
	printf("请输入题目数量>");
	two_1();
}
void operation_3()
{
	printf("请输入题目数量>");
	three_1();
}
void one_1()
{
	int n, a, b, c;
	scanf_s("%d", &n);
	printf("一年级题目如下：
");
	srand((unsigned)time(NULL));
	for (int i = 1; i <= n; i++)
	{
		a = rand() % 10 + 1;
		b = rand() % 10 + 1;
		c = rand() % 2;
		if (c == 0)
			printf("%2d + %2d = ___", a, b);
		else
			printf("%2d - %2d = ___", a, b);
		printf("
");
	}
}
void two_1()
{
	int n, a, b, c;
	scanf_s("%d", &n);
	printf("二年级题目如下：
");
	srand((unsigned)time(NULL));
	for (int i = 1; i <= n; i++)
	{
		a = rand() % 100;
		b = rand() % 100;
		c = rand() % 2;
		if (c == 0)
			printf("%3d * %3d = ___", a, b);
		else
			printf("%3d / %3d = ___", a, b);
		printf("
");
	}
}
void three_1()
{
	int n, a, b, c;
	scanf_s("%d", &n);
	printf("三年级题目如下：
");
	srand((unsigned)time(NULL));
	for (int i = 1; i <= n; i++)
	{
		a = rand() % 100;
		b = rand() % 100;
		c = rand() % 4;
		switch (c)
		{
		case 0:printf("%3d + %3d = ___", a, b); break;
		case 1:printf("%3d - %3d = ___", a, b); break;
		case 2:printf("%3d * %3d = ___", a, b); break;
		case 3:printf("%3d / %3d = ___", a, b); break;
		}
		printf("
");
	}
}

2.2.5Gitee上传截图与链接

https://gitee.com/xiaodanfeng