#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int randomNumber()    //生成一个随机数
{
    int a = rand() % 10+1;
    return a;
}

int printfNumber()   //打印数字并读取用户输入，正确返回1，错误返回0
{
    int num_1, num_2,userInput;
    num_1 = randomNumber();
    num_2 = randomNumber();

    char a;
    int i;
    i = rand() % 4;
    switch (i)   //随机产生一个运算符
    {
    case 0: a = '+'; break;
    case 1: a = '-'; break;
    case 2: a = '*'; break;
    case 3: a = '/'; break;
    default: printf("error"); break;
    }

    printf("%d %c %d = ", num_1,a, num_2);
    scanf("%d", &userInput);

    float calculateResult;
    switch (a)    //计算正确结果
    {
    case '+': calculateResult = num_1 + num_2; break;
    case '-': calculateResult = num_1 - num_2; break;
    case '*': calculateResult = num_1 * num_2; break;
    case '/': calculateResult = num_1 / num_2; break;
    }

    if (calculateResult == userInput)  return 1;
    if (calculateResult != userInput)  return 0;

}

void randomRight()  //随机产生一个正确提示语
{
    int i = rand() % 4;
    switch (i)
    {
    case 0:printf("Very good!\n"); break;
    case 1:printf("Excellent!\n"); break;
    case 2:printf("Nice work!\n"); break;
    case 3:printf("Keep up the good work!\n"); break;
    default:printf("error\n"); break;
    }
}

void randomWrong()   //随机产生一个错误提示语
{
    int i = rand() % 4;
    switch (i)
    {
    case 0:printf("No.Please try again.\n"); break;
    case 1:printf("Wrong.Try once more.\n"); break;
    case 2:printf("Don't give up!\n"); break;
    case 3:printf("Not correct.Keep trying.\n"); break;
    default:printf("error\n"); break;
    }
}

int main()
{
    printf("*****************************************************************\n");
    printf("**                  小学生学习四则运算辅助系统                 **\n");
    printf("**     按下1进入有重做机会的测试 按下2进入无重做机会的测试     **\n");
    printf("*****************************************************************\n");

    int a = getchar();

    srand(time(0));

    if (a == '1')   //进入可以重做三次的测试
    {
        int i, j = 0, k = 0, m;
        //i用于控制十次答题，j计算正确的次数，k计算错误的次数
        for (i = 0; i < 10; i++)
        {
            m = printfNumber();
            if (m==1)
            {
                j++;
                k = 0;
                randomRight();
            }
            if (m==0)
            {
                k++;
                if (k < 3)
                {
                    randomWrong();
                }
                if (k == 3)   //错误三次 结束
                {
                    printf("Wrong!You have tried 3 times, test over.\n");
                    break;
                }
            }    
        }
            
        
    }

    if (a == '2')    //进入无重做机会的测试
    {

        int i, j = 0, k = 0, m, flag = 0;
        //i用于控制十次答题，j计算正确的次数，k计算错误的次数
        //flag为0时正确率小于75，为1时大于75

        do
        {
            for (i = 0; i < 10; i++)
            {
                m = printfNumber();
                if (m == 1)
                {
                    j++;
                    randomRight();
                }
                if (m == 0)
                {
                    k++;
                    randomWrong();
                }
            }

            printf("Your score is %d,accuracy is %d%%.\n", 10 * j, 10 * j);
            flag = 1;

            if (10 * j < 75)
            {
                printf("Again!\n");
                flag = 0;
            }
        } while (flag == 0);
        

        

    }

    return 0;
}

除法会出现一些问题，暂时不知道怎么改