calculating a function

[romeoz]

here is the code quzah starte for me and I added the cout and cin but I'm unsure where to add the PowerInt(n) =(n!)/n^2 formula. I think I should be adding that somewhere because it states how to test the variable that is entered or am I completly wrong?

#include <iostream>
#include <stdlib.h>

using namespace std;

int main()

float p(int i)

{
    if( i < 10 && i > 1 )
    {
        int x = i*i;
             y; 
        float z 

        cout << "enter a number" << endl;
cin >> z;

        return z / (float)x;
    }
    return 1.0;
}

[ZakkWylde969]

#include <iostream>
#include <stdlib.h>

using namespace std;

int main();    //Took an error out when I added semicolon 

float p(int i)

{
    if( i < 10 && i > 1 )
    {
        int x = i*i;
        int y;    ///Needed variable int
        float z;    ///Forgot semicolon 

        cout << "enter a number" << endl;
cin >> z;

        return z / (float)x;
    }
    return 1.0;
}

That fixed it when I compiled. I got these 2 errors when I tried to build however.

Compiling...
Cpp1.cpp
c:\compiled\float\cpp1.cpp(14) : warning C4101: 'y' : unreferenced local variable
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/Cpp1.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

Cpp1.exe - 2 error(s), 1 warning(s)

I might be wrong just trying to help though

[quzah]

Ug. No that's not what I started. Well actually, it's part of what I started, used incorrectly. 'p' is a function. It is not a part of main. Before 'y', that was a , not a ;

Furthermore, the answer was given in your original thread. You ignored the second point of my illustration. Just read the original thread and pay attention to the provided code.

Quzah.

[romeoz]

well I added a few things, sorry about that. I guess this program is just really hard. I'm going to look in the text book again and see if I cant put your examples and their examples together and figure somethign out.

Bryan

[subdene]

this again, i thought this was resolved.

[romeoz]

I made up a new code, and it seems to work for the most part until it tries to calculate the PowerInt. I know where my problem is but I cant seem to make the n! do what it should. It needs to multiply. If user enters a 4 then it needs to multiply 1*2*3*4/4^2 but I cant seem to make it do that. Any more suggestions.

Thanks

#include <iostream>

using namespace std;

int main()

{
	int iNum;		//stores input value
	int iSum;		//stores sum

	cout << "Please enter an interger: "; //user enters number
	cin >> iNum;	 //letter stored
	

	while (iNum >= 1 && iNum <= 10)
	{
		iSum = iNum!/iNum*iNum; //THIS IS MY PROBLEM
			
		cout << "PowerInt" <<"(" << iNum << ") =" <<iSum << endl;
		
		cout << "Please enter an interger: ";
		cin >> iNum;
		


	}

	cout << "Exiting the program." << endl;
	return 0;
}

[confuted]

>> iSum = iNum!/iNum*iNum; //THIS IS MY PROBLEM
Yes it is. First, use some parentheses. Second... ! does not do a factorial in C++ - it's a logical negation. You're going to have to code a factorial function...

int factorial(int number)
{
   int result=1;
   for(int t=number;t=1;t--)
      result*=t;
   return result;
}

Use it like this

iSum=factorial(iNum)/(iNum*iNum);

[romeoz]

so if I use the code for factorial, which is what i was looking for, I would replace my erro with iSum=fac. ect. But where can I enter the code that you wrote in my program to make it work?

#include <iostream>
#include <iomanip>

using namespace std;

int main()

{
	int iNum;		//stores input value
	int iSum;		//stores sum
	
	cout << "Please enter an interger: "; //user enters number
	cin >> iNum;						; //letter stored
	
	


	while (iNum >= 1 && iNum <= 10)
	{
		iSum=factorial(iNum)/(iNum*iNum); //where do I input that code you wrote to make this not undefined?
		
		cout << "PowerInt" <<"(" << iNum << ") ="  <<iSum << endl;
		
		cout << "Please enter an interger: ";
		cin >> iNum;
		


	}

	cout << "Exiting the program." << endl;
	return 0;
}

[Perspective]

>> //where do I input that code you wrote to make this not undefined?

somewhere before main()

[confuted]

or stick the line
int factorial(int number);
before int main() and then stick the function that I wrote at the end of your program.

[romeoz]

I figured out what the n factroail should look like with your help and researching the book more, but it still dont work out. I get this error when trying to build it. error C2601: 'factorial' : local function definitions are illegal

#include <iostream>

using namespace std;

int main()

{
	int iNum;		//stores input value
	int iSum;		//stores sum
	
	int factorial (int iNum)
	{                              //ITS POINTING TO THIS BRACKET
		int result;

	result = 1;
	while (iNum > 0)
	{
		result = result * iNum;
		iNum--;
	}
	return result;
	}
	
	while (iNum >= 1 && iNum <= 10)
	{
		iSum=factorial(iNum)/(iNum*iNum);

		cout << "Please enter an interger: "; //user enters number
		cin >> iNum;						; //letter stored
		cout << "PowerInt" <<"(" << iNum << ") ="  <<iSum << endl;

		
		cout << "Please enter an interger: ";
		cin >> iNum;
		


	}

	cout << "Exiting the program." << endl;
	return 0;
}

[confuted]

Change your code to look like this

#include <iostream>

using namespace std;

int factorial(int iNum);

int main()

{
	int iNum;		//stores input value
	int iSum;		//stores sum
	
	while (iNum >= 1 && iNum <= 10)
	{
		iSum=factorial(iNum)/(iNum*iNum);

		cout << "Please enter an interger: "; //user enters number
		cin >> iNum;						; //letter stored
		cout << "PowerInt" <<"(" << iNum << ") ="  <<iSum << endl;
		
		cout << "Please enter an interger: ";
		cin >> iNum;
	}

	cout << "Exiting the program." << endl;
	return 0;
}

int factorial (int iNum)
{                             
	int result;

	result = 1;
	while (iNum > 0)
	{
		result = result * iNum;
		iNum--;
	}
	return result;
}

[ZakkWylde969]

blackrat did you even run your program? It goes right to the exiting the program string.

[JaWiB]

int iNum;		//stores input value
	int iSum;		//stores sum
	
	while (iNum >= 1 && iNum <= 10)

so what does iSum and iNum == there??

int factorial (int iNum)
{                             
	int result;

	result = 1;
	while (iNum > 0)
	{
		result = result * iNum;
		iNum--;
	}
	return result;
}

will always return 0

[romeoz]

thanks for everyone who helped me with this. I appreciate it so much. After a few days of this I finally got it. I could not get them to print out in decimals becuase I was putting int iNum and int iSum and they needed to be float iNum and float iSum...it works great now. thanks again

//**************************
//This program calculates
//an n! factorial
//**************************

#include <iostream>

using namespace std;

int factorial(int iNum);		//number whose factorial is to be computed

int main()

{

	float iNum;		//stores input value
	float iSum;		//stores sum
	 

	do
	{
		cout << "Please enter an interger: "; //user enters number
		cin >> iNum;						; //letter stored
		if (iNum<=-1)break;			//if negative number program will end
		iSum=factorial(iNum)/(iNum*iNum); //call to factorial 
		cout << "PowerInt" <<"(" << iNum << ") ="<<iSum << endl; //output

	}while(true);		//if true program will exit
	cout << "Exiting the program." << endl;	//end program
	
	return 0;
}

int factorial (int iNum)				//n! factorial 
{                             
	int result;

	result = 1;
	while (iNum > 1)
	{
		result = result * iNum;
		iNum--;
	}
	return result;
}