Question

想打印例如等级：4/5 80％ 程序询问用户他们想要解决多少数学问题并打印出错误的数量/权利的数量＆＃34;和他们的成绩。我想我在代码的最后没有我的数学因为它的打印输出例如：等级：4/5 -7446528％

+++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++

# include <stdio.h>

int main()
{
    int NumberOfTimes, AddAns, SubAns, AddCorrect=0, SubCorrect=0, CorrectAnsAdd, CorrectAnsSub, TotalCorrect, TotalWrong, Add;
    int i,a,b,c,d,e,f,g;
    float percent;

    printf("\n");
    printf("-------------------MATH QUIZ------------------------\n");
    printf("Enter the number of Math problems you want to solve:"); //enters the # of problems the program produces
    scanf("%d", &NumberOfTimes);
    printf("\n");
    srand(time(NULL));
    //Random number generator
    for (i=0;i<NumberOfTimes;++i)
    {
        b = rand() %3 + 1;
        c = rand() %3 + 1;
        a = rand() %2 + 1;

        //Random addition problems
        if (a == 1)
        {
            printf("%d + %d = ", b,c);
            scanf("%d", &AddAns);
            d = b + c;
            if (AddAns == d)
            {
                printf("  +Correct\n");
                AddCorrect = AddCorrect + 1;
            }
            //Random subtraction problems
            else
            {
                printf("  +Wrong, it was %d\n", d);
                AddIncorrect = AddIncorrect + 1;
            }
        }
        if (a == 2)
        {
            printf("%d - %d = ", b,c);
            scanf("%d", &SubAns);
            g = b - c;
            //Produces right or wrong answers
            if (SubAns == g)
            {
               printf("  +Correct\n");
               SubCorrect = SubCorrect + 1;
            }
            else
            {
                printf("  +Wrong, it was %d\n", g);
                SubIncorrect = SubIncorrect + 1;
            }
        }
    }
    //Producing the output to wrong/right numbers and grade percentage 
    TotalCorrect = AddCorrect + SubCorrect;
    printf("\n");
    printf("Grade: %d/%d\n",TotalCorrect,NumberOfTimes);
    printf("\n");
    percent=NumberOfTimes/TotalCorrect;
    printf("%d percent \n", percent);
    return 0;
}

Answer 1

有一些事情正在发生。首先，要使用float打印printf，请使用%f。 %d用于int s。

其次，当你计算percent时，你会意外地使用整数除法。由于NumberOfTimes和TotalCorrect都是整数，NumberOfTimes/TotalCorrect执行整数除法并生成int。在评估整个初始化表达式之后，它只转换为float 。请改用：

percent = (float)TotalCorrect / NumberOfTimes; // OR, if you want an actual percent: percent = 100.0f*TotalCorrect/NumberOfTimes;

然后，使用%f：

printf("%f percent\n", percent); // "80.000000 percent"

请注意，这会显示多个小数位的百分比;如果您想要一个没有小数点的清洁显示，您可以将百分比计算为int：

// multiply before dividing to avoid integer division problems int percent = 100*TotalCorrect/NumberOfTimes; printf("%d percent\n", percent); // "80 percent"

希望这有帮助！

Answer 2

在C中，除非指向浮点数，否则除以两个整数将不会得到浮点数。这就是语言的运作方式。你必须将NumberOfTimes和TotalCorrect强制转换为浮点数。

所以更换 percent=NumberOfTimes/TotalCorrect;与

percent=(float)TotalCorrect/(float)NumberOfTimes * 100;

此外，您尝试在行

中打印一个整数浮点数

printf("%d percent \n", percent);

这给你一个不稳定的结果。相反，尝试：

printf("%d percent \n", (int)percent);

C程序：简单的数学程序

2 个答案: