# Little Man Computer: Factorial Challenge In Mathematics, the factorial of n is denoted by n! and calculated by the product of integer numbers from 1 to n.

For instance: In this challenge you will write a program using Little Man Computer to ask the user to enter a positive number. In return the program will output the factorial of this number.

Before completing this challenge, we recommend you to have a go at:

#### Multiplication using LMC

While checking the Little Man Computer Instruction Set (See table at the bottom of this post), you will have noticed that, through there are two instructions for adding (ADD) and subtracting (SUB) numbers, there is no instruction for multiplying two numbers.

The solution to overcome this, is two consider a multiplication as a series of additions. For instance:

5 * 4 = 5 + 5 + 5 + 5

Find out more: Little Man Computer: Multiplication

#### Iteration using LMC

To apply an iterative approach for this challenge we will use branching options: Little Man Computer: 5 + 4 + 3 + 2+ 1.

This challenge will add a level of complexity as we will be using a nested loop approach: one loop to list all the multiplications to be performed (e.g. 4! = 4 * 3 * 2 * 1) and one loop for implementing each multiplication as a series of additions. (e.g. 4 * 3 = 4 + 4 + 4)

#### Solution

This solution also caters for the fact that 0! = 1. This is the purpose of line 3, 34,35 and 36.