Thread: while loop question

Code:

#include <cstdlib> 
#include <ctime>
#include <iomanip>
#include <iostream>

using namespace std; // prototype and name space declaration
int sqr(int);
int cube(int);
int fourthPower(int);
int fifthPower(int);
int sixthPower(int);
bool printNum();
void show(int (*fn)(int), int); 

//------------------------------------------------------------------
//------------------------------------------------------------------
//------------------------------------------------------------------

void main()
{	
	
	printNum();

}
//------------------------------------------------------------------
//------------------------------------------------------------------
//------------------------------------------------------------------

bool printNum()
{
	char input;
	int block =0;

	cout<< "To Square The Number Enter: S"<<endl;
	cout<< "To Cube The Number Enter: C"<<endl;
	cout<< "To the Fourth Power of The Number Enter: F"<<endl;
	cout<< "To the Fifth Power of The Number Enter: T"<<endl;
	cout<< "To the Sixth Power of The Number Enter: X"<<endl;
	cout<< "To Quit: Q"<<endl;
	cin >> input;
	
	while ( input!= int('s') || input !=int('S')
		|| input != int('c') || input !=int('C')
		|| input != int('f') || input !=int('F')
		|| input != int('t') || input !=int('T')
		|| input != int('x') || input !=int('X')
		|| input != int('q') || input !=int('Q'))
	{		
			if ( input == int('q') || input ==int('Q'))
		{
		cout << "Program Ended. "<<endl;
			return 0;
		}
		cout << "Wrong Choice.\n";
		cout << "Enter Again: ";
		cin.clear();
		cin.ignore(80,'\n');
		cin >> input;
	}

			
	while (true)

		{

			int lowVal ,maxVal;


			cout <<"Enter A Number For Low Bound: ";
			cin >> lowVal;
					
			while ( !cin.good() ||( lowVal < 0 || lowVal >100 )) // validation  
			{

				cout << "Positive Numbers Only.\n";
				cout << "Enter Again: ";
				cin.clear();
				cin.ignore(80,'\n');
				cin >> lowVal;
			}
			cout << "Enter A Number For Upper Bound : ";
			cin >> maxVal;

			while ( !cin.good() || maxVal < lowVal || maxVal >100 ) 
			{
				cout << "Positive Numbers Only.\n";
				cout << "Upper Bound Can' Be Smaller Than Lower Bound";
				cout << "Enter Again: ";
				cin.clear();
				cin.ignore(80,'\n');
				cin >> maxVal;
			}
		
			if ( (lowVal == 0 && maxVal == 0))
				printNum();

			cout <<"Printing "<<(maxVal-lowVal)+1<<" numbers"<<endl;

			for (int x = lowVal; lowVal<=maxVal; lowVal++)
			{
				if (input == int('s') || input == int('S'))
				{
					cout.setf(ios::left);
					cout<< setw(5);
					show(sqr, lowVal);
					block++;
				}
				else if (input == int('c') || input == int('C'))
				{
					cout.setf(ios::right);
					cout<< setw(5);
					show(cube, lowVal);
					block++;
				}
				else if (input == int('f') || input == int ('F'))
				{
					cout.setf(ios::right);
					cout<< setw(8);
					show(fourthPower, lowVal);
					block++;
				}
				else if (input == int('t') || input == int ('T'))
				{
					cout.setf(ios::right);
					cout<< setw(10);
					show(fifthPower, lowVal);
					block++;
				}
				else if (input == int('x') || input == int ('X'))
				{
					cout.setf(ios::right);
					cout<< setw(10);
					show(sixthPower, lowVal);
					block++;
				}
				if (block == 10)
				{
					block = 0;
					cout<<"\n";
				}
			}
			cout <<"\n";
			block = 0;
			
	}

   
}
//------------------------------------------------------------------
//------------------------------------------------------------------
//------------------------------------------------------------------
int sqr(int num) // list of functions 
{
    return num * num;
}

int cube(int num) // this one is to cube
{
    return num * num * num;
}
int fourthPower(int num)
{
    return num * num * num * num;
}
int fifthPower(int num)
{
    return num * num * num * num * num;
}

int sixthPower(int num)
{
    return num * num * num * num * num * num;
}

void show(int (*fn)(int), int num) // pointer
{
    cout << fn(num);

1)i am offering user 6 options, s,S,c,C...q and Q
if user inputs s for square and then the program will prompt user to input 2 number one for upper and one for lower bound.
afterward i will display all the number in between the boundary and square all the numbers
and prints them.
after the print it will ask the user again for a new sets of boundary and if the user inputs 2 0's. my program will bring up the original prompt and start fresh again.

2)the loop i set i want it to catch the user input if they enter anything other than s,S,c,C..q and Q. i will display a error message and ask for input again.

3)i entered this
input output
2 wrong input
a wrong input
s wrong input
q quit

4)when i enter q the i am surprise program ends, but when i enter s or any of the characters in the option i offer my loop will keep re promote for another input why.