# New program need help with factorials

• 05-20-2005
New program need help with factorials
I need to know how to find the factorial (5!=125) of a variable and, using it and for loops, put all of the possible combinations in an array.
• 05-20-2005
hk_mp5kpdw
Quote:

I need to know how to find the factorial (5!=125) of a variable

Use a loop to calculate the factorial.

Quote:

and, using it and for loops, put all of the possible combinations in an array.

Huh? Combinations of what into the array?
• 05-20-2005
xErath
factorial of x is x*factorial(x-1), and factorial 0 is 1
have fun... I'd sugest a cicle instead of recursion... recursion does functions call, which have a big overhead and use lots of stack.
• 05-20-2005
Togra
Quote:

5!=125

Close... 5! = 120.
• 05-20-2005
DougDbug

Do you know what a factorial is? Can you do it by hand or on a calculator? ... I mean a calculator without a factorial button.

5! means 1 x 2 x 3 x 4 x 5 = 120. (Of course, that's NOT C++ because x does NOT mean multiply in C++.) :)

Step 1
If you can't figure-out the whole program, how about starting with a loop that generates the sequential integers 1 thru n: 1, 2, 3, 4...

Step 2
When that's working, add the code to calculate the factorials.

Step 3
When you get that working, add the array stuff.

I assume that by "all the possible combinations" you mean this all of the factorials up to n: 1, 2, 6, 24...