Anyway, despite the difficulties, I am now done with problem 34 and with trying to write project euler solution type problems in batch.

Also, I am pretty sure this program now takes the prize for most lines of code I have written for a solution for this challenge. (not counting the writing of the Shakespeare compiler)
@echo off goto main rem *I originally wrote this factorial method, but it rem *is slower than the lookup method, which is plenty rem *suitable for the needs of this problem :factorialreal set /a counter=1 set /a result=0 :loop1 set /a test=input+1 if "%counter%"=="%test%" ( goto end ) else ( set /a result*=%counter% ) set /a counter+=1 goto loop1 :end1 goto aftercall :factorial if %input%==0 ( set /a result=1 ) else if %input%==1 ( set /a result=1 ) else if %input%==2 ( set /a result=2 ) else if %input%==3 ( set /a result=6 ) else if %input%==4 ( set /a result=24 ) else if %input%==5 ( set /a result=120 ) else if %input%==6 ( set /a result=720 ) else if %input%==7 ( set /a result=5040 ) else if %input%==8 ( set /a result=40320 ) else ( set /a result=362880 ) goto aftercall :main rem *we check all possible sums of factorials with reasonable digit rem *frequencies and see if these sums are the sums of the factorials rem *of their digits. This is really big and sloppy...but oh well, rem *and the brute-force method (check all numbers from 1 to an upperbound, rem *see if that number is the sum of the factorial of its digits) was rem *far too slow set /a test=0 set /a answer=0 set /a c1=0 :loop-01 set /a c2=0 :loop-2 set /a c3=0 :loop-3 set /a c4=0 :loop-4 set /a c5=0 :loop-5 set /a c6=0 :loop-6 set /a c7=0 :loop-7 set /a c8=0 :loop-8 set /a c9=0 :loop-9 set /a test+=c1 set /a test+=c2*2 set /a test+=c3*6 set /a test+=c4*24 set /a test+=c5*120 set /a test+=c6*720 set /a test+=c7*5040 set /a test+=c8*40320 set /a test+=c9*362880 set /a j=test set /a digifacsum=0 :testloop if %digifacsum% GTR %test% ( goto endtest ) if %j%==0 ( goto endtest ) set /a input=j %% 10 set /a j/=10 goto factorial :aftercall set /a digifacsum+=result goto testloop :endtest if %test% GTR 10 ( if %digifacsum%==%test% ( set /a answer+=test ) ) set /a test=0 if not %c9%==0 ( set /a c9+=1 goto loop-9 ) :end9 if not %c8%==1 ( set /a c8+=1 goto loop-8 ) :end8 if not %c7%==1 ( set /a c7+=1 goto loop-7 ) :end7 if not %c6%==1 ( set /a c6+=1 goto loop-6 ) :end6 if not %c5%==2 ( set /a c5+=1 goto loop-5 ) :end5 if not %c4%==3 ( set /a c4+=1 goto loop-4 ) :end4 if not %c3%==3 ( set /a c3+=1 goto loop-3 ) :end3 if not %c2%==2 ( set /a c2+=1 goto loop-2 ) :end2 if not %c1%==2 ( set /a c1+=1 goto loop-01 ) :end01 echo %answer%