Computer-aided-instruction environment questions

[cykaleblyat]

I'm writing a CAI program to help kids learn math and I am running into a few logic errors. Other resources I have tried to use to debug the program have been unhelpful thusfar. The program works at lower difficulty levels most of the time, but at higher maximum number counts and random operations the program shows a number of bugs. For debugging purposes, I've told the program to output the correct answer after the user inputs their own.

- At a difficulty level of 5, where the operation applied to the two numbers is random, the display function does not correctly choose which operation to perform and leaves the string as "default". Why is this the case?

- When numbers are large, the correct answer is an overflow value instead of an actual number despite being within the data value limit of a double.

- The program loops infinitely when anything other than a number is inputted by the user. This can be solved if I allow the answer to be a string, but that would make things very messy. Is there a way around this?

#include <iostream>
#include <cmath>
#include <string>
#include <ctime>
#include <cstdlib>

using namespace std;

void generate(double  &a, double &b, int diff, int mathtype)
{
	
	switch (diff)
	{
	case 1:
		a = (rand() % 10);
		b = (rand() % 10);
		break;
	case 2:
		a = (1 + rand() % 99);
		b = (1 + rand() % 99);
		break;
	case 3:
		a = (1+rand() % 999);
		b = (1+rand() % 999);
		break;
	}
	
}


void display(double a, double b, int mathtype, int diff, int opp)
{
	string(operation) = "default";

	if (diff <= 5)
	{
		opp = (rand() % 4 + 1);
		switch (opp)
		{
		case 1:
			operation = "plus";
			break;
		case 2:
			operation = "minus";
			break;
		case 3:
			operation = "divided by";
			break;
		case 4:
			operation = "times";
			break;
		}
	}

	switch (mathtype)
	{
	case 1:
		cout << "What is " << a << " plus " << b << "?" << endl;
		break;
	case 2:
		cout << "What is " << a << " minus " << b << "?" << endl;
		break;
	case 3:
		cout << "What is " << a << " divided by " << b << "?" << endl;
		break;
	case 4:
		cout << "What is " << a << " times " << b << "?" << endl;
		break;
	case 5:
		cout << "What is " << a << " " << operation << " " << b << "?" << endl;
	
	}

}

void percent(int &c, int &total, char choice, bool choices)
{
	double score = 0;
	score = static_cast <double> (c) / static_cast<double>(total);
	if (score <= .75)
	{
		cout << "This is too hard for you, just give up" << endl;
		cout << "Your average is " << score*100 << "%" << endl;
		total = 0;
		c = 0;
		
	}
	else
	{
		cout << "You passed, go away and let someone else use the program" << endl;
		cout << "Your average is " << score*100 << "%" << endl;
		total = 0;
		c = 0;
	}
}


void correct(int i, int &total, int &c, char choice, bool choices)
{
	int q = rand() % 4 + 1;
	total++;
	c++;
	switch (q)
	{
		
	case 1:
		cout << "Cool, you can math, do it " << 10 - i << " more times" << endl;
		
		break;
	case 2:
		cout << "Riveting, do it " << 10 - i << " more times" << endl;
		break;
	case 3: 
		cout << "Wow you totally smashed that one, do it " << 10 - i << " more times" << endl;
		break;
	case 4: 
		cout << "This answer isn't incorrect, do it " << 10 - i << " more times" << endl;
		break;
	}
	if (total >= 10)
	{
		percent(c, total, choice, choices);
	}

}

void incorrect(int usr, double ans, int &total, int &c, char choice, bool choices)
{


	cout << "Looks like you can't do math, try again" << endl;

	do
	{
		
		cin >> usr;
		
		int q = rand() % 4 + 1;

		switch (q)
		{
	
		case 1:
			cout << "Wow, you're pretty stupid" << endl;
		total++;
			
			break;
		case 2:
			cout << "You have no future" << endl;
			total++;
			
			break;
		case 3:
			cout << "That is easy, you are not trying" << endl;
			total++;
			
			break;
		case 4:
			cout << "Your IQ is even lower than projected" << endl;
			total++;
			
			break;
		}
		if (total == 10)
		{
			percent(c, total, choice, choices);
		}

	} while (usr != ans);

}

void compare(int usr, double &ans, int i, double a, double b, int &c, int &total, char choice, bool choices, int opp, int diff, int mathtype)
{ 

	if (diff == 5)
	{
		switch (opp)
		{
		case 1:
			ans = a + b;
			break;
		case 2:
			ans = a - b;
			break;
		case 3:
			ans = a / b;
			break;
		case 4:
			ans = a * b;
			break;
		}
	}
	else
	{
		switch (mathtype)
		{
		case 1:
			ans = a + b;
			break;
		case 2:
			ans = a - b;
			break;
		case 3:
			ans = a / b;
			break;
		case 4:
			ans = a * b;
			break;
		}
	}
	
	cout << ans << endl;

	if (usr != ans)
	{
		incorrect(usr, ans, total, c, choice, choices);
	}
	else if (usr == ans)
	{
		correct(i, total, c, choice, choices);
	}
}

void clear()
{
	for (int i = 0; i <= 10; i++)
	{
		cout << endl;
	}
}

int main()
{
	srand(time(0));
	double a, b, ans;
	int usr, diff, mathtype, opp=0;
	int c=0, total=0;
	char choice = 'y';
	bool choices = true;
	
	while (choices != false)
	{ 
		cout << "Enter the maximum count of digits from 1 to 3" << endl;
		cin >> diff;
		cout << "Enter the operation you want to practice: 1 is addition, 2 is subtrction, 3 is division, 4 is multiplication, and 5 is random" << endl;
		cin >> mathtype;
		for (int i=0; i < 10; i++ )
		{
			generate(a, b, diff, mathtype);
			display(a, b, mathtype, diff, opp);
			cin >> usr;
			compare(usr, ans, i, a, b, c, total, choice, choices, opp, diff, mathtype);

		}

		clear();
		choices = true;
		
	}
	

	return 0;
}

[coder777]

Line 33 looks strange. Better remove the parentheses.

Line 35: Why do you use diff here? Isn't it the number of digits?

Line 37: opp will not be changed outside display(...) because it is not passed by reference. I'd suggest that you omit opp and modify mathtype instead (you would need to pass it by reference as well).