v0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

v0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001

>"d">1-:!#v_:03p013p"~I"+23p>23g"d"%1+23g"d"/g"0"-03g*13g+:55+%68 v

^ $# _^#!p32:-1g32p31/+55p/"d"g32+1%"d"g32+*<

>"~I"+33p0>33g"d"%1+33g"d"/g"0"-+ 33g:1-33p v

@._^#! <

[0,3] current multiplicand

[1,3] carry

[2,3] multiplication index

[3,3] sum index

---------------------------------------

The approach is similar to problem 16 - the main task was implementing a long multiplication algorithm in Befunge.

Then, after 100! is calculated we only need to sum the individual digits.