haha

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


struct calls
	{
		int a,b,c,temp,i,count,tries=0,correct=0;
	};


void addition(difficulty, struct calls call);
void subtraction(difficulty);
void multiplication(difficulty);
void diff(int difficulty);


int main()
{
	int difficulty;
	srand(time(NULL));

	int choice;
	float percent;

	printf ("Please Choose Difficulty Level:\n[1]-Easy\n[2]-Medium\n[3]-Hard\n");
	scanf ("%i",&difficulty);
	diff(difficulty);

	printf ("Choose your Math Type:\n[1] - Addition\n[2] - Subtraction\n[3] - Multiplication\n");
	scanf ("%i",&choice);
		switch(choice)
		{
			case 1: addition(difficulty,struct calls call);
			break;

			case 2: subtraction(difficulty);
			break;

			case 3: multiplication(difficulty);
			break;

			default : NULL;
			break;
		}



	printf ("Amount Correct :%i\nTries :%i\n",correct,tries);
	percent = ((float)correct/(float)tries)*100;
	printf ("Percent: %2.2f %%\n",percent);
	system("PAUSE");
	return 0;

}

void diff(int difficulty)
{

		switch(difficulty)
		{
			case 1 : calls.a=rand()%19+1;
					 calls.b=rand()%8+1;
					 break;

			case 2: calls.a=rand()%99+1;
			 		calls.b=rand()%49+1;
			 		break;

			case 3: calls.a=rand()%249+1;
					calls.b=rand()%149+1;
					break;

			default : NULL;
			break;
		}
}

void addition(difficulty, struct calls call)
{
	struct calls call
	printf ("How many questions would you like:");
	scanf ("%i",&calls.count);

	for (calls.i=0;calls.i<calls.count;calls.i++)
	{

	do{
		diff(difficulty);
			 //a=rand()%19+1;
			 //b=rand()%8+1;

			 if (calls.b > calls.a)
			 	{
				 calls.temp = calls.a;
			 	 calls.b = calls.a;
			 	 calls.a = calls.temp;
				}

	printf("%3i\n",calls.a);
	printf("+%2i\n",calls.b);
	printf("---\n");
	scanf ("%i",&calls.c);
	printf("\n");
	calls.tries++;

	while(calls.c != (calls.a+calls.b))
		{
		printf ("Please try again:");
		scanf ("%i",&calls.c);
		calls.tries++;
		}

	}while(calls.c != (calls.a+calls.b));

	calls.correct++;
	}
}

void subtraction(difficulty)
{

	printf ("How many questions would you like:");
	scanf ("%i",&count);

	for (i=0;i<count;i++)
	{

	do{
		diff(difficulty);
			// a=rand()%19+1;
			 //b=rand()%8+1;

			 if (b > a)
			 	{
				 temp = a;
			 	 b = a;
			 	 a = temp;
				}

	printf("%3i\n",a);
	printf("-%2i\n",b);
	printf("---\n");
	scanf ("%i",&c);
	printf("\n");
	tries++;

	while(c != (a-b))
		{
		printf ("Please try again:");
		scanf ("%i",&c);
		tries++;
		}

	}while(c != (a-b));

	correct++;
	}
}

void multiplication(difficulty)
{

	printf ("How many questions would you like:");
	scanf ("%i",&count);


	for (i=0;i<count;i++)
	{

	do{
		diff(difficulty);
			// a=rand()%11+1;
			 //b=rand%4+1;

			 if (b > a)
			 	{
				 temp = a;
			 	 b = a;
			 	 a = temp;
				}

	printf("%3i\n",a);
	printf("x%2i\n",b);
	printf("---\n");
	scanf ("%i",&c);
	printf("\n");
	tries++;

	while(c != (a*b))
		{
		printf ("Please try again:");
		scanf ("%i",&c);
		tries++;
		}

	}while(c != (a*b));

	correct++;
	}
}