四则运算

| 这个作业属于哪个课程|https://edu.cnblogs.com/campus/ahgc/AHPU-SE-19|
| ---- | ---- | ---- |
|这个作业要求在哪里|https://edu.cnblogs.com/campus/ahgc/AHPU-SE-19/homework/11376|
| 这个作业的目标 | 能够有选择的自动生成四则运算并判断正误以及正确率 |
| 学号 | 3190704139|

|

include<stdio.h>

include<stdlib.h>

include<time.h>

include<windows.h>

include<string.h>

define OPERATOR 4

//获取随机数
int random(double start, double end)

{
return (int)(start + (end - start)*rand() / (RAND_MAX + 1.0));
}

//整数列式
void equation() {
int num1;
int num2;
int result;
int answer;
char button;
int right=0;
float accuracy;
int i, n;
printf("请输入要生成的式子数：");
scanf("%d", &n);
printf("请按1-4键选择题目\n1:加法\n2:减法\n3:乘法\n4:除法：");//选择要进行的运算
scanf("%d", &button);
for (i = 0; i < n; i++) {
srand((unsigned)time(NULL));
num1 = random(0, 20);
num2 = random(1, 20);
switch (button)
{
case 1: result = num1 + num2;
printf("%d+%d=\n", num1, num2); break;
case 2: result = num1 - num2;
printf("%d-%d=\n", num1, num2); break;
case 3: result = num1num2;
printf("%d%d=\n", num1, num2); break;
case 4: num1 = num1num2;
result = num1 / num2;
printf("%d÷%d=\n", num1, num2);
break;
}
//printf("%d%c%d=\n", num1, oper, num2);
printf("请输入你的答案：");
scanf("%d", &answer);
if (result==answer) {
printf("恭喜你答对了\n\n");
right++;
}
else {
printf("对不起答错了\n");
printf("正确答案为：%d\n\n", result);
}
}
accuracy = ((float)right /(float) n)100;
printf("正确率为百分之%1.2f\n", accuracy);
}

//真分数列式

void fraction() {

int num1,num2,num3,num4;
int a, b;
int answer1, answer2;
float result;
float answer;
char button;
int right = 0;
float accuracy;
int i, n;
printf("请输入要生成的式子数：");
scanf("%d", &n);
printf("请按1-4键选择题目\n1:加法\n2:减法\n3:乘法\n4:除法：");
scanf("%d", &button);
for (i = 0; i < n; i++) {
    srand((unsigned)time(NULL));
    num1 = random(0, 20);
    num2 = random(1, 20);
    num3 = random(0, 20);
    num4 = random(1, 20);
    switch (button)
    {
    case 1: 
        a = num1*num4+num3*num2;
        b = num2*num4;
        result = (float)a / (float)b;
        printf("%d/%d+%d/%d=\n", num1, num2, num3, num4); break;
    case 2: 
        a = num1*num4 - num3*num2;
        b = num2*num4;
        result = (float)a / (float)b;
        printf("%d/%d-%d/%d=\n", num1, num2, num3, num4); break;
    case 3:  
        a = num1*num3;
        b = num2*num4;
        result = (float)a / (float)b;
        printf("%d/%d*%d/%d=\n", num1, num2,num3, num4); break;
    case 4: 
        a = num1*num4;
        b = num2*num3;
        result =(float) a /(float) b;
        printf("%d/%d÷%d/%d=\n", num1, num2, num3, num4);
        break;
    }
    printf("请输入你的答案：\n");
    scanf("%d", &answer1);
    printf("/\n");
    scanf("%d", &answer2);//判断所输入答案的正确性
    answer = (float)answer1 / (float)answer2;
    if (result==answer) {
        printf("恭喜你答对了\n\n");
        right++;
    }
    else {
        printf("对不起答错了\n");
        printf("正确答案为：%d/%d\n\n", a,b);
    }
}
accuracy = ((float)right / (float)n) * 100;
printf("正确率为百分之%1.2f\n", accuracy);

}

//主函数

void main() {
int choose;
printf("输入1生成整数算式，其他生成分式算式：");
scanf("%d", &choose);
if (choose == 1) {
equation();
}
else {
fraction();
}
}

`