# Math Tutor Solution

This program will ask the user to answer a series of arithmetic problems and report on how the user performs. You will write this program in the following phases. Make sure that each phase works correctly and is stylistically perfect before progressing to the following phase.

Note that the purpose of this assignment is to give you lots of practice with parameter passing without making you write a huge program. For this reason I have provided a structure diagram at the end of this document. Make sure that you adhere to the structure diagram carefully and DO NOT use global variables. Turn in only your final product.

Phase I: Your main function for phase I must look exactly like this:

int main()

{

srand(time(0));

doOneSet();

}

You must write the function doOneSet which will, for now, write out 5 addition problems. All of the numbers in your programs should be between 0 and 100. Here is the sample output for this phase:

45 + 21 =

0 + 100 =

54 + 23 =

4 + 19 =

8 + 92 =
The numbers that are produced for these problems must be generated randomly by the computer. The numbers in the sample output are given only as an example. We will discuss in the lessons how to generate random numbers.

Phase II: Change your doOneSet function so that instead of just writing out the problems it also allows the user to enter an answer, and then tells the user whether the answer was correct or not. Do not change your main function. Here is the sample output for this phase (user input is indicated here by using bold font. It won't be bold in your own output):

45 + 21 = 66

correct

0 + 100 = 100

correct

54 + 23 = 67

incorrect

4 + 19 = 13

incorrect

8 + 92 = 100

correct

Phase III: Now you will change your doOneSet function so that it will work for either addition, subtraction, or multiplication. For the purposes of this assignment, a set of problems is defined to be a group of problems that are all of the same type (all addition, all subtraction, or all multiplication). After completing this phase your program will give 5 addition problems, 5 subtraction problems, and 5 multiplication problems, for a total of 15 problems. Your main function must look exactly like this:

int main()

{

srand(time(0));

doOneSet('+');

doOneSet('-');

doOneSet('*');

}
The parameter tells doOneSet whether to do addition, subtraction, or multiplication. Notice that there is exactly one doOneSet function definition, not three! Here is the sample output for this phase:

45 + 21 = 66

correct

0 + 100 = 100

correct

54 + 23 = 67

incorrect

4 + 19 = 13

incorrect

8 + 92 = 100

correct

59 - 19 = 40

correct

19 - 84 = -29

incorrect

0 - 65 = -65

correct

96 - 1 = 95

correct

94 - 14 = 80

correct

0 * 87 = 0

correct

45 * 84 = 398

incorrect

8 * 37 = 873

incorrect

34 * 83 = 831

incorrect

38 * 3 = 238

incorrect
Note: Do not proceed on from phase III until you are sure your program is perfect and you have checked to make sure that you have adhered to structure diagram given at the end of this document!!!

Phase IV: Now you are ready to let the user specify how many problems per set. However, due to certain new software use guidelines the user is allowed between 3 to 10 problems per set per run of the program. (Recall that a set is a group of problems all of the same type. In this program we are doing three sets: one set of addition, one set of subtraction, and one set of multiplication. This means that, for example, if the problems per set is 7, there will be a total of 21 problems given.) As per the new guidelines, ask the user to enter only the acceptable number of problems per set at the very beginning of the program, so that all three sets have the same number of problems per set. Now your main function will look exactly like this (you may add variable declarations only):

int main()

{

int probsPerSet;

srand(time(0));

getProbsPerSet(probsPerSet);

doOneSet('+', probsPerSet);

doOneSet('-', probsPerSet);

doOneSet('*', probsPerSet);

}
For this phase you should also add a header at the beginning of each set, as illustrated in the following sample output for this phase. For purposes of the header, you should assume that the addition problems will always be set #1, the subtraction problems set #2, and the multiplication problems set #3.

Enter problems per set: 3

Set #1

----------

45 + 21 = 66

correct

0 + 100 = 100

correct

54 + 23 = 67

incorrect

Set #2

----------

59 - 19 = 40

correct

19 - 84 = -29

incorrect

0 - 65 = -65

correct

Set #3

----------

0 * 87 = 0

correct

45 * 84 = 398

incorrect

8 * 37 = 873

incorrect

Phase V: Now let the user specify maxNum, the maximum number to be used for each set. This means that instead of choosing numbers between 0 and 100 (inclusive) for each problem, the computer will be choosing numbers between 0 and maxNum (inclusive). You must allow the user to enter a different maximum number for each set. This won't change the main function, since you need to ask it again before each set. It will be done near the beginning of your doOneSet function. Here's the sample screen output:

Enter problems per set: 3

Set #1

----------

What is the maximum number for this set? 100

45 + 21 = 66

correct

0 + 100 = 100

correct

54 + 23 = 67

incorrect

Set #2

----------

What is the maximum number for this set? 90

59 - 19 = 40

correct

19 - 84 = -29

incorrect

0 - 65 = -65

correct

Set #3

----------

What is the maximum number for this set? 20

0 * 18 = 0

correct

15 * 4 = 398

incorrect

8 * 17 = 873

incorrect
Phase VI: Now you need to keep track of how the user is doing. At the end of the program, write a report which says how many the user got right on each set out of how many and for what percent. Also tell the overall figures. Here's the sample screen output:

Enter problems per set: 3

Set #1

----------

What is the maximum number for this set? 100

45 + 21 = 66

correct

0 + 100 = 100

correct

54 + 23 = 67

incorrect

Set #2

----------

What is the maximum number for this set? 90

59 - 19 = 40

correct

19 - 84 = -29

incorrect

0 - 65 = -65

correct

Set #3

----------

What is the maximum number for this set? 20

0 * 18 = 0

correct

15 * 4 = 398

incorrect

8 * 17 = 873

incorrect

Set#1: You got 2 correct out of 3 for 67%

Set#2: You got 2 correct out of 3 for 67%

Set#3: You got 1 correct out of 3 for 33%

Overall you got 5 correct out of 9 for 56%
Your main function for phase VI must look like this (you may add variable declarations and arguments only):

int main()

{

int probsPerSet;

int set1Correct,set2Correct, set3Correct;

srand(time(0));

getProbsPerSet(<arguments);

doOneSet(<no-more-than-3-arguments);

doOneSet(<no-more-than-3-arguments);

doOneSet(<no-more-than-3-arguments);

printReport(<arguments);

}
Please note that you may send no more than 3 arguments to doOneSet. Hint: Although main will need three separate variables to keep track of the number of problems answered correctly in each set, your doOneSet function will have only one parameter which keeps track of the number of problems answered correctly in the current set. It will be up to main to get that information into the correct variable.

The following structure diagram includes every function that you will have in your program. You should have no more and no fewer, and you should use the names that have been suggested here. Functions pictured below that are not labeled with a phase should be implemented at least by phase III. Please also read the notes below the structure diagram very carefully.

Notes:

• Note: The doOneProblem function does exactly one problem, not one *type* of problem!!

• Please change getNumbers to generateOperands

• CheckAnswer is the function that writes either "correct" or "incorrect"

• You will receive a 0 on this assignment if you use global variables, arrays or structs and your final source code submitted does not include nine functions in addition to int main as shown in the structure diagram above.

• Turn in only phase VI, of your final product.

• You will lose points if the code you put in one of your functions does not correspond to the name of the function given in the structure diagram.

• Finally your program should be properly formatted, with nine function prototypes listed above the main function and all the related functions defined below main. Make sure to include appropriate function related documentation* (ie., data flow comments in all function parameter lists, a description of what the function does above the each function definition and any pre and post conditions in the function heading area)

Please make sure to place a comment near each of your function definitions, use good decomposition, separate your functions with at least 1 inches of whitespace and DO NOT use global variables. I suggest that now would be a good time to reread the How To Get Good Grades on Your Programs and Function Documentation: Assertions and Dataflow comments. Note: Projects submitted without appropriate function related documentation will not be graded and you will need to resubmit your source code including all function related documentation.