这个项目有多个错误。第一个也是最重要的一个必须是我在一个案例中回答一个问题。而不是回到选择案例，而是转向困难。这不会让我退出程序并使平均问题正确。
另一个错误是结束平均问题是正确的。每当我试图跳过问题并结束时，我的程序就会崩溃。除非那是不可能的，否则它只会除以0/0。我应该使用一个开关功能，这是我见过的循环问题。可悲的是，我无法找到一种方法来解决这个问题，或者每一个答案都在我的头上。
#include <stdio.h>
int main()
{
int option = 0;
int answer = 0;
int remainder = 0;
int ttlProblems = 0;
int correctAnswers = 0;
double averageCorrect = 0;
char difficulty;
printf("Math Practice Program Menu");
printf("\n\n1. Addition\n");
printf("2. Subtraction \n");
printf("3. Multiplication \n");
printf("4. Division \n");
printf("5. Exit\n\n");
printf("Select an option: ");
scanf_s("%d", &option);
while (option != 5)
{
switch (option)
{
case 1:
printf("Select difficulty level...\ne for easy\nm for medium\nh for hard\n");
scanf_s(" %c", &difficulty, 1);
if (difficulty == 'e')
{
printf("3 + 1 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 4)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'm')
{
printf("34 + 19 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 53)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'h')
{
printf("134 + 119 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 253)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else
{
printf("Invalid difficulty set\n");
}
break;
case 2:
printf("Select difficulty level...\ne for easy\nm for medium\nh for hard\n");
scanf_s(" %c", &difficulty, 1);
if (difficulty == 'e')
{
printf("3 - 1 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 2)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'm')
{
printf("34 - 19 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 15)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'h')
{
printf("134 - 119 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 15)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else
{
printf("Invalid difficulty s\n");
}
break;
case 3:
printf("Select difficulty level...\ne for easy\nm for medium\nh for hard\n");
scanf_s(" %c", &difficulty, 1);
if (difficulty == 'e')
{
printf("3 * 1 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 3)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'm')
{
printf("34 * 19 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 646)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'h')
{
printf("134 * 119 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
if (answer == 15946)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else
{
printf("Invalid difficulty set\n");
}
break;
case 4:
printf("Select difficulty level...\ne for easy\nm for medium\nh for hard\n");
scanf_s(" %c", &difficulty, 1);
if (difficulty == 'e')
{
printf("9 / 2 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
printf("Enter any remainder: ");
scanf_s("%d", &remainder, 1);
if (answer == 4 && remainder == 1)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'm')
{
printf("34 / 19 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
printf("Enter any remainder: ");
scanf_s("%d", &remainder, 1);
if (answer == 1 && remainder == 15)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else if (difficulty == 'h')
{
printf("134 / 19 = ? Enter answer: ");
scanf_s("%d", &answer, 1);
printf("Enter any remainder: ");
scanf_s("%d", &remainder, 1);
if (answer == 7 && remainder == 1)
{
++ttlProblems;
++correctAnswers;
printf("Correct!\n");
}
else
{
++ttlProblems;
printf("Sorry, Incorrect\n");
}
}
else
{
printf("Invalid difficulty set\n");
break;
}
break;
case 5:
break;
default:
printf("Not a valid option.\n");
}
}
averageCorrect = ttlProblems / correctAnswers;
printf("You attempted %d problems and got %d correct\nFor a percentage of %.2f correct.", ttlProblems, correctAnswers, averageCorrect);
}
答案 0 :(得分：0)
目前，您的代码要求用户在while循环之前输入选项类型，因此它只会询问一次并在每次循环迭代时将该值用于该选项。将选项输入scanf_s("%d", &option);移动到while循环的开头可以解决您的第一个问题。
关于除以零，这将导致程序崩溃，因为它不可能。在执行除法之前，您可能想要检查correctAnswers是否为零。