# 四则运算

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
2）程序要求能处理用户的输入，判断对错，累积分数
3）程序支持可以由用户自行选择加、减、乘、除运算
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

1.设计思路
①需求分析:


②功能设计:

2.源代码

# include <string.h>

using namespace std;
typedef struct //定义分数结构体
{
int up, down;
}fraction;
int gcd(int a, int b) //最大公约数
{
if (b == 0) return a;
return gcd(b, a % b);
}
void yuefen(int &a, int &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);
}
}
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,i;
for (i = 0; i <=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\n", i+1, a, b); //输出整数题目
}
for (i = num/2+1; i < 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("\n"); //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;
}
}

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,i;
for (i = 0; i <= 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\n", i, a, b);
}
for (i = num / 2 + 1; i < 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("\n");
fraans[i].up = up1 * down2 - up2 * down1;
fraans[i].down = down1 * down2;
flag = 1;
yuefen(fraans[i].up, fraans[i].down, flag);
flag = 0;
}
}

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,i;
for (i = 0; i <= 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\n", i+1, a, b);
}
for (i = num / 2 + 1; i < 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("\n");
fraans[i].up = up1 * up2;
fraans[i].down = down1 * down2;
flag = 1;
yuefen(fraans[i].up, fraans[i].down, flag);
flag = 0;
}
}

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 < 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(" \n");
fraans[i].up = up1 * down2;
fraans[i].down = down1 * up2;
flag = 1;
yuefen(fraans[i].up, fraans[i].down, flag);
flag = 0;
}
}

int main()
{
char f = 'Y';
while(f!='N'&&f!='n')
{
fraction fraans[400], userfraans[400];
int ans[100] = { 0 }, userans[100] = { 0 },i;
int num, symbol, grade = 0;
printf("四则运算题目生成程序\n");
printf("请选择符号,1,2,3,4对应加减乘除：");
scanf("%d", &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("%d", &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 ( i = 0; i <= num / 2; i++)
{
printf("第%d道题的答案为：", i + 1);
scanf("%d", &userans[i]);
}
for ( i = num / 2 + 1; i < num; i++)
{
printf("第%d道题的答案为：", i + 1);
if (fraans[i].down == 1)
{
scanf("%d", &userfraans[i].up);
userfraans[i].down = 1;
}
else
{
scanf("%d/%d", &userfraans[i].up, &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 ( i = 0; i < num; i++)
{
printf("第%d道题的答案为：", i + 1);
if (fraans[i].down == 1)
{
scanf("%d", &userfraans[i].up);
userfraans[i].down = 1;
}
else
{
scanf("%d/%d", &userfraans[i].up, &userfraans[i].down);
}
}
}
for ( i = 0; i <= 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 ( i = num / 2 + 1; i < num; i++)
{
if (userfraans[i].up == fraans[i].up && userfraans[i].down == fraans[i].down)grade++;
}
printf("是否继续做题？(Y/N)");
cin >> f;
if (f != 'N' && f != 'n')system("cls");
else return 0;
}


}

3.运行截图

psp2.1 任务内容 计算完成需要的时间（min) 实际完成需要的时间(min)
Planning 计划 5 5
Estimate 估计这个任务需要多少时间，并规划大致工作步骤 10 12
Development 开发 150 180
Analysis 需求分析 12 15
Design Spec 生成设计文档 4 4
Design Review 设计复审 5 10
Coding Standard 代码规范 3 5
Design 具体设计 10 15
Coding 代码 30 50
Code Review 代码复审 5 8
Test 测试 6 10
Reporting 报告 6 9
Test Report 测试报告 3 3
Size Measurement 计算工作量 2 2
Postmortem & Process Improvement Plan 事后总结，并提出过程改进计划 5 5

posted @ 2020-11-07 19:56  krisDaytoy  阅读(82)  评论(0编辑  收藏  举报