四则运算

| 这个作业属于哪个课程 | <a href="https://edu.cnblogs.com/campus/ahgc/AHPU-se-JSJ18/">软件工程</a> |

|----------------------- |------------------------------|

| 这个作业要求在哪里 | <a href="https://edu.cnblogs.com/campus/ahgc/AHPU-se-JSJ18/homework/11377">作业要求</a>|

| 这个作业的目标 | <能对需求进行分析并实现；编码格式规范；学习博客撰写> |

| 学号 | <3180701304> |

<p></p><div class="toc"><div class="toc-container-header">目录</div><ul><li><a href="#题目要求">题目要求</a></li><li><a href="#函数说明">函数说明</a><ul><li><a href="#分数结构体">分数结构体</a></li><li><a href="#找公约数">找公约数</a></li><li><a href="#分数约分">分数约分</a></li><li><a href="#加法">加法</a></li><li><a href="#减法">减法</a></li><li><a href="#乘法">乘法</a></li><li><a href="#除法">除法</a></li><li><a href="#主函数">主函数</a></li></ul></li><li><a href="#运行截图">运行截图</a><ul><li><a href="#加法">加法</a></li><li><a href="#减法">减法</a></li><li><a href="#乘法">乘法</a></li><li><a href="#除法">除法</a></li></ul></li><li><a href="#小结">小结</a></li><li><a href="#源码">源码</a></li></ul></div><p></p>
	<h1 id="题目要求">题目要求</h1>
	<p>写一个能自动生成小学四则运算题目的程序，然后在此基础上扩展：</p>
	<p>1）除了整数以外，还要支持真分数的四则运算，例如：1/6+1/8=7/24</p>
	<p>2）程序要求能处理用户的输入，判断对错，累积分数</p>
	<p>3）程序支持可以由用户自行选择加、减、乘、除运算</p>
	<p>4）使用-n参数控制生成题目的个数，例如Myapp.exe -n 10，将生成10个题目</p>

<h1 id="函数说明">函数说明</h1>
	<h2 id="分数结构体">分数结构体</h2>
	<pre><code>typedef struct //定义分数结构体
	{
	int up, down;
	}fraction;
	</code></pre>
	<h2 id="找公约数">找公约数</h2>
	<pre><code>int gcd(int a, int b) //最大公约数
	{
	if (b == 0) return a; //辗转相除法
	return gcd(b, a % b);
	}
	</code></pre>
	<h2 id="分数约分">分数约分</h2>
	<pre><code>void yuefen(int &amp;a, int &amp;b,int flag) //分数约分，并自动进行输出，用flag标志答案，答案不输出
	{
	int d = gcd(abs(a), abs(b));
	a /= d;
	b /= d;
	if (flag == 0) {
	if (b == 1)printf("%d", a);
	else printf("%d/%d", a, b);
	}
	}
	</code></pre>
	<h2 id="加法">加法</h2>
	<pre><code>void add(int num,fraction fraans[],int ans[]) //加法题目生成及运算
	{
	int a, b, up1, down1, up2, down2,flag=0;
	for (int i = 0; i &lt;=num / 2; i++) //整数部分
	{
	unsigned int times = (unsigned int)time(0); //生成随机数
	srand(times * (i + 1));
	a = rand() % 10 + 1;
	b = rand() % 10 + 1;
	ans[i] = a + b;
	printf("%d.%d+%d ", i+1, a, b); //输出整数题目
	}
	for (int i = num/2+1; i &lt; num; i++) //分数部分
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	up1 = rand() % 10 + 1;
	down1 = rand() % 10 + 1;
	up2 = rand() % 10 + 1;
	down2 = rand() % 10 + 1;
	printf("%d.", i + 1);
	yuefen(up1, down1,flag);
	printf("+");
	yuefen(up2, down2,flag);
	printf(" "); //将随机生成的分数进行约分后再输出
	fraans[i].up = up1 * down2 + up2 * down1;
	fraans[i].down = down1 * down2;
	flag = 1; //用flag标志答案，对答案不进行输出
	yuefen(fraans[i].up, fraans[i].down,flag);
	flag = 0;
	}
	}
	</code></pre>
	<h2 id="减法">减法</h2>
	<pre><code>void subtract(int num, fraction fraans[], int ans[]) //减法题目生成及运算
	{
	int a, b, up1, down1, up2, down2,flag=0;
	for (int i = 0; i &lt;= num / 2; i++)
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	a = rand() % 10 + 1;
	b = rand() % 10 + 1;
	ans[i] = a - b;
	printf("%d.%d-%d ", i, a, b);
	}
	for (int i = num / 2 + 1; i &lt; num; i++)
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	up1 = rand() % 10 + 1;
	down1 = rand() % 10 + 1;
	up2 = rand() % 10 + 1;
	down2 = rand() % 10 + 1;
	printf("%d.", i + 1);
	yuefen(up1, down1, flag);
	printf("-");
	yuefen(up2, down2, flag);
	printf(" ");
	fraans[i].up = up1 * down2 - up2 * down1;
	fraans[i].down = down1 * down2;
	flag = 1;
	yuefen(fraans[i].up, fraans[i].down, flag);
	flag = 0;
	}
	}
	</code></pre>
	<h2 id="乘法">乘法</h2>
	<pre><code>void multiply(int num, fraction fraans[], int ans[]) //乘法题目生成及运算
	{
	int a, b, up1, down1, up2, down2,flag = 0;
	for (int i = 0; i &lt;= num / 2; i++)
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	a = rand() % 10 + 1;
	b = rand() % 10 + 1;
	ans[i] = a * b;
	printf("%d.%d*%d ", i+1, a, b);
	}
	for (int i = num / 2 + 1; i &lt; num; i++)
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	up1 = rand() % 10 + 1;
	down1 = rand() % 10 + 1;
	up2 = rand() % 10 + 1;
	down2 = rand() % 10 + 1;
	printf("%d.", i + 1);
	yuefen(up1, down1, flag);
	printf("*");
	yuefen(up2, down2, flag);
	printf(" ");
	fraans[i].up = up1 * up2;
	fraans[i].down = down1 * down2;
	flag = 1;
	yuefen(fraans[i].up, fraans[i].down, flag);
	flag = 0;
	}
	}
	</code></pre>
	<h2 id="除法">除法</h2>
	<pre><code>void divide(int num, fraction fraans[])
	{ //除法题目生成及运算
	int up1, down1, up2, down2, flag = 0;
	for (int i = 0; i &lt; num; i++)
	{
	unsigned int times = (unsigned int)time(0);
	srand(times * (i + 1));
	up1 = rand() % 10 + 1;
	down1 = rand() % 10 + 1;
	up2 = rand() % 10 + 1;
	down2 = rand() % 10 + 1;
	printf("%d.(", i + 1);
	yuefen(up1, down1, flag);
	printf(")/(");
	yuefen(up2, down2, flag);
	printf(") ");
	fraans[i].up = up1 * down2;
	fraans[i].down = down1 * up2;
	flag = 1;
	yuefen(fraans[i].up, fraans[i].down, flag);
	flag = 0;
	}
	}
	</code></pre>
	<h2 id="主函数">主函数</h2>
	<pre><code>int main()
	{
	char f = 'Y';
	while(f!='N'&amp;&amp;f!='n')
	{
	fraction fraans[400], userfraans[400];
	int ans[100] = { 0 }, userans[100] = { 0 };
	int num, symbol, grade = 0;
	printf("四则运算题目生成程序 ");
	printf("请选择符号,1,2,3,4对应加减乘除：");
	scanf_s("%d", &amp;symbol); //用symbol标志用户选择的符号，1234对应加减乘除；
	printf("请输入题目数量(最少为2，最大100)：");
	scanf_s("%d", &amp;num);
	switch (symbol) //对应选择不同的算法
	{
	case 1:add(num, fraans, ans); break;
	case 2:subtract(num, fraans, ans); break;
	case 3:multiply(num, fraans, ans); break;
	case 4:divide(num, fraans); break;
	}
	if (symbol != 4) //当用户选择的运算不为除法时，分别对整数和分数答案进行保存
	{
	for (int i = 0; i &lt;= num / 2; i++)
	{
	printf("第%d道题的答案为：", i + 1);
	scanf_s("%d", &amp;userans[i]);
	}
	for (int i = num / 2 + 1; i &lt; num; i++)
	{
	printf("第%d道题的答案为：", i + 1);
	if (fraans[i].down == 1)
	{
	scanf_s("%d", &amp;userfraans[i].up);
	userfraans[i].down = 1;
	}
	else
	{
	scanf_s("%d/%d", &amp;userfraans[i].up, &amp;userfraans[i].down);
	}
	}
	}
	else //当用户选择为出发时，对用户输入的答案进行保存
	{
	for (int i = 0; i &lt; num; i++)
	{
	printf("第%d道题的答案为：", i + 1);
	if (fraans[i].down == 1)
	{
	scanf_s("%d", &amp;userfraans[i].up);
	userfraans[i].down = 1;
	}
	else
	{
	scanf_s("%d/%d", &amp;userfraans[i].up, &amp;userfraans[i].down);
	}
	}
	}
	for (int i = 0; i &lt;= num / 2; i++) //对用户输入的答案和答案进行对比，如果一致，得分+1
	{
	if (userans[i] == ans[i])grade++;
	}
	for (int i = num / 2 + 1; i &lt; num; i++)
	{
	if (userfraans[i].up == fraans[i].up &amp;&amp; userfraans[i].down == fraans[i].down)grade++;
	}
	printf("grade=%d ", grade);
	printf("是否继续做题？(Y/N)");
	cin &gt;&gt; f;
	if (f == 'Y')system("cls"); //清屏
	else return 0;
	}
	}