Project Euler #20 and 100!
It’s after 2am on the West coast. I am still awake. As a mental distraction, I’ve been doing working through the problems on Project Euler. Tonight, in need of a distraction, I started working on Problem 20.
Sum the digits in 100!. Looking around I couldn’t find much information on factoral values. They are simple enough in the lower range.
5! = 120
6! = 720
With that info I can validate that my formula for finding factorals is correct. Things get a bit sketchier when I asked for 20! This is what Google spits out:
20 ! = 2.43290201 × 1018
Scientific notation isn’t much help for what I want to do. I know I’ve got the right values, but it nags at me that I can’t find what I need online. So, I added a couple more lines to my code to spit out each value in turn.
