Another stupid C++ question

[techteen143]

Alright how can I make this program add the "count" numbers individually to get the factorial of the integer? Obviously this does not work. I am pretty stupid....

// purpose: Calculate and print product of the integers 1 through n

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

int main(void)
{
	int n, nfact;
   cout << "This program will calculate the factorial of a positive integer. ";
   cout << "Input Integer" << endl;
   cin >> n;
   for(int count = 1; count <= n; count ++)
   	{
		nfact = count + count;
        }
   cout << "The value of " << n << "! is: " << nfact << endl;
   system("pause");
return 0;
}

Thanx

[jkrohn]

Try this

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

int main(void)
{
   int n, nfact=1;
   cout << "This program will calculate the factorial of a positive integer. ";
   cout << "Input Integer" << endl;
   cin >> n;
   for(int count = 1; count <= n; count ++)
   {
	nfact = nfact * count;
   }
   cout << "The value of " << n << "! is: " << nfact << endl;
   system("pause");
return 0;
}

Jkrohn

[techteen143]

Didn't work when I put in 7 I get 5040 not 28. My brain is off tonight...
Thanx tho

[jkrohn]

7! is 5040.....

I don't see the problem....

Jkrohn

[techteen143]

supposed to be 1+2+3+4+5+6+7 or is that somethin else? That is wha I need... 7 is supposed to return 28...

[jkrohn]

n! = 1*2*3*4......*n

If you are looking for the sum of consecutive integers up to n then use this code.

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

int main(void)
{
     int n, nfact=0;
     cout << "This program will calculate the sum of consectutive integers from 1 to n. ";
     cout << "Input Integer" << endl;
     cin >> n;
     for(int i=1; i <= n;  i++)
     {
           nfact += i;
     }
     cout << "The value of the consecutive integers is"<<nfact;
     system("pause");
  return 0;
}

Jkrohn

[techteen143]

Thanx but what exactly does
nfact += i do?

[jkrohn]

nfact += 1;

is "shorthand" for

nfact = nfact + i;

Jkrohn

[techteen143]

Thanx havent gotten that far

-Techteen143

[techteen143]

Got another question: What can I put here to make this program work?

// purpose: Price value table

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

int main(void)
{
	cout.precision(2);
   cout.setf(ios::showpoint);
   cout.setf(ios::fixed,ios::floatfield);
   int TotalNumber;
   double UnitPrice;
   cout << "How many units do you want to buy?" << endl;
   cin >> TotalNumber;
   cout << "What is the unit price?" << endl;
   cin >> UnitPrice;
   cout << "Number of Units\t Total Price" << endl;
   cout << "===============\t ===========" << endl;
   for(int counter = 1; counter <= TotalNumber; counter ++)
   	{
	cout << "\t" << counter << "\t   $" << UnitPrice << endl;
        UnitPrice = ;  
	}
   system("pause");
return 0;
}

Ex. 
input 5 & 1.50
# of units         total price
    1                       1.50
    2                       3.00
    3                       4.50
               etc...

Thanx