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%
