Factorial Calculator
July 27, 2009 4 Comments
If n is an integer greater than 0, n factorial (n!) is the product: n* (n-1) * (n-2) * ( n-3)… *
By convention, 0! = 1. You must write a program that allows a user to enter an integer between 1 and 7. Your program must then compute the factorial of the number entered by the user.
Your solution MUST actually perform a computation (i.e., you may not simply print “5040” to the screen as a literal value if the input is 7).
Example 1:
Enter a number: 4
4! = 24
Example 2:
Enter a number: 7
7! = 5040
Solution in C/C++:
#include <stdio.h>
int main ()
{
printf ("Enter a number: ");
int n;
scanf ("%d", &n);
int factorial = 1;
for ( int i = 1; i <= n; i++ )
factorial = factorial * i;
printf ("%d! = %d\n", n, factorial );
return 0;
}
Solution in Python:
import sys
sys.stdout.write ('Enter a number: ')
n = int (input ())
factorial = 1
for i in range (1, n + 1) :
factorial *= i
print ('%d! = %d' % (n, factorial))
There are another way to solve this problem
solution:
#include <stdio.h> //#include int rec(int num); int main() { int number; int rezult; printf("Enter a number: "); scanf("%d",&number); rezult = rec(number); printf("%d! = %d\n",number,rezult); //system(“PAUSE”); return 0; } int rec(int num) { if(num == 1) return 1; /* else */ return (num * rec(num-1)); }#include
int func(int);
int main()
{int a,b,c,i;
printf(“enter a number “);
while(scanf(“%d”,&a)!=EOF)
{
c=func(a);
printf(“%d!=%d”,a,c);
}
return 0;}
int func(int a)
{int b;
if(a==1)
return 1;
else
while(a!=1)
{
b=a*func(a-1);
return b;
}
}
May i have the problem number and problem site name. I couldn’t find any reference here.
Here is an example written in VB
Console.Write(“Enter a number: “)
Dim num As Integer = Console.ReadLine
Dim total As Integer = num
For i As Integer = 1 To num – 1
total = total * (num – i)
Next
Console.WriteLine(total.ToString)
Console.ReadLine()