Algorithm to find the factorial of a number entered by user.

Step 1: Start
Step 2: Declare variables n,factorial and i.
Step 3: Initialize variables
          factorial←1
          i←1
Step 4: Read value of n
Step 5: Repeat the steps until i=n
     5.1: factorial←factorial*i
     5.2: i←i+1
Step 6: Display factorial
Step 7: Stop