C++ help

[Game4564]

write a set of functions that will be used by an interactive menu-driven program that will perform various calculations and operations. A menu of calculation types will be shown to a user at the beginning of the program (and again after each calculation). This menu will be implemented as a function (more details to follow). The user will select an option and the program will then prompt for additional information that is specific to the type of operation to be performed, perform the operation, and display the results of that operation. This process will continue until the user decides to quit.


Sample output*******************

Special Purpose Calculator

1) Average
2) Factorial
3) M to the Nth Power
4) Range

Q) Quit

What would you like to do? 5

5 is an invalid selection. Try again: 9
9 is an invalid selection. Try again: 1

Enter the sum value ( -1000 - 1000 ): 750
Enter the count value ( 1 - 1000 ): 43

The average is 17.44


Special Purpose Calculator

1) Average
2) Factorial
3) M to the Nth Power
4) Range

Q) Quit

What would you like to do? 2

Enter a number ( 0 - 8 ):-9

Error: -9 is not between 0 and 8. Try again:9
Error: 9 is not between 0 and 8. Try again: 6

The factorial of 6 is 720


Special Purpose Calculator

1) Average
2) Factorial
3) M to the Nth Power
4) Range

Q) Quit

What would you like to do? 3

Enter the M value ( 0 - 20 ): 7
Enter the N value ( 1 - 7 ): 4

The result of raising 7 to the 4th power is 2401


Special Purpose Calculator

1) Average
2) Factorial
3) M to the Nth Power
4) Range

Q) Quit

What would you like to do? 4

Enter a number ( -100 - 100 ): 0
Enter a number ( -100 - 100 ): -89
Enter a number ( -100 - 100 ): 78
Enter a number ( -100 - 100 ): 6

The range of 0, -89, 78 and 6 is 167


Special Purpose Calculator

1) Average
2) Factorial
3) M to the Nth Power
4) Range

Q) Quit

What would you like to do? Q

  The following is what I have but it isn't working right.
 
#include <iostream>
#include <iomanip>
using namespace std;
// Function Prototypes
string Menu();
int getValue(string, int, int);
void doAverage();
double calcAverage(int, int);
void doFactorial();
int calcFactorial(int);
void doMtoNth();
int calcMtoNth(int, int);
void doRange();
int calcRange(int, int, int, int);
 
int main()
{
string userChoice;
userChoice=Menu();
//while loop
while (userChoice != "Q" and userChoice != "q")
{
if (userChoice == "1")
{
doAverage();
}
else if (userChoice == "2")
{
doFactorial();
}
else if (userChoice == "3")
{
doMtoNth();
}
else if (userChoice == "4")
{
doRange();
}
userChoice = Menu();
}
return 0;
}
//string menu
string Menu()
{
string userChoice;
cout<< "Special Purpose Calculator"<<endl
 <<endl
 << "1) Average"<<endl
 << "2) Factorial "<<endl
 << "3) M to the Nth Power"<<endl
 << "4) Range"<<endl
 <<endl
 << "Q) Quit"<<endl
 <<endl;
cout<< "Enter your choice? ";
cin >> userChoice;
return userChoice;
}

//int getValue
int getValue(string prompt, int lowBound, int upBound)
{
int number;
cout<< prompt<< lowBound<<" and "<<upBound<<": ";
do
{
if (number < lowBound or number > upBound)
{
cout<<endl<<"Error: "<<number<<" is invalid. Try again: ";
}
}
while (number < lowBound or number > upBound);
return number;
}

//void doAverage
void doAverage()
{
string state1="Enter a sum to be averaged between ";
string state2="Enter the number of entries ";
//declare variables
int lowBoundA = 1;
int upBoundA = 1000;
int lowBoundB = 1;
int upBoundB = 1000;
int sum;
int count;
double average;
sum=getValue(state1, lowBoundA, upBoundA);
count=getValue(state2, lowBoundB, upBoundB);
average=calcAverage(sum, count);
cout<<endl<<"The average is: ";
return;
}
//doulble calcAverage
double calcAverage( int sum, int count )
{
double average;
average=(double) sum/count;
return average;
}

//void doFactorial
void doFactorial()
{
string state1="Enter a number between: ";

//declare variables
int lowBound = 0;
int upBound = 10;
int numfactorial;
int factorial;
numfactorial=getValue(state1, lowBound, upBound);
factorial=calcFactorial(numfactorial);
return;
}
//int calcFactorial
int calcFactorial(int number)
{
int count,
factorial=1,
numfactorial;
count=numfactorial;
cout<<endl<<"The factorial value is: ";
while (count > 0)
{
factorial=factorial*count;
cout <<count<<endl<< "x";
count--;
}
cout<<" = "<<factorial;
return factorial;
}

//void doMtoNth
void doMtoNth()
{
string state1="Enter a value: ";
string state2="Enter a value: ";
//Declare variables
int lowBoundA=1;
int upBoundA = 10;
int lowBoundB = 1;
int upBoundB = 8;
int M;
int N;
int MtoNth;
double average;
M=getValue(state1, lowBoundA, upBoundA);
N=getValue(state2, lowBoundB, upBoundB);
MtoNth=calcMtoNth (M, N);
cout<<endl<<M<<" to the "<<N<< "th power is: ";
cout<<MtoNth;
return;
}

//int calcMtoNth
int calcMtoNth(int M, int N)
{
//Declare Variables
int MtoNth=1;
int count = 1;
int Nth;
while (count <= Nth)
{
MtoNth *=M;
count ++;
}
return MtoNth;
}

//void doRange
void doRange()
{
string state1="Enter a number between ";
string state2="Enter another number between ";
//Declare variables
int lowBound = 0;
int upBound = 1000;
int num1;
int num2;
int num3;
int num4;
int range=0;
double average;
num1=getValue(state1, lowBound, upBound);
num2=getValue(state2, lowBound, upBound);
num3=getValue(state2, lowBound, upBound);
num4=getValue(state2, lowBound, upBound);
range=calcRange(num1, num2, num3, num4);
cout<<endl<<"The range of " <<num1<<", "<<num2<<", "<<num3<<", "<<num4<<"is "<<range;
return;
}

//int calcRange
int calcRange(int number1, int number2, int number3, int number4)
{
//Declare variables
int max;
int min;
int range;
if (number1 >= number2)
max = number1;
else
max = number2;
if (number3 >= max)
max = number3;
if (number4 >= max)
max = number4;
if (number1 <= number2)
min = number1;
else
min = number2;
if (number3 <= min)
min = number3;
if (number4 <= min)
min = number4;
range = max - min;
return range;
} 

[Chervil]

it isn't working right.

Though there is a lot of background information here, the actual question is vague. Could you clarify what is the nature of the problem is, which part do you need help with?

[Mats]

Why not simplify the user choice part and get rid of that error?

while(userinput != "1" || userinput != "2" || userinput != "3" || userinput != "4")
{
    cout << "Enter choice: "; 
    cin >> userinput; 
} 

I think you probably have more errors, but I'm not going to go through and find every error in the code. Tell us the specifics so we don't have find them.