C Case in loop problems - c

Question

I have multiple errors with this project. The first and most important one would have to be one I answer a question in a case. Rather than it going back to choosing a case, it instead goes towards the difficulty. This won't let me exit the program and to get the average questions correct.
Another error is the end average questions correct. My program crashes whenever I try to just skip questions and go to the end. All it would do is divide 0/0 unless that's not possible. I'm supposed to use a switch function which is something I've seen has a problem with loops. Sadly, I can't find a way to fix it on my end, or every answer has just gone right over my head.
#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);
}

Answer 1

Currently, your code asks the user to enter the option type before the while loop, so it will only ask once and use that value for the option every loop iteration. Moving your option input scanf_s("%d", &option); into the beginning of the while loop should solve your first problem.
In regards to dividing by zero, this will cause the program to crash because it is not possble. You might want to check whether correctAnswers is zero or not before performing the division.