
Post by svajoklis on May 12, 2020 8:12:31 GMT 5
Hello again. It was nice to see your solutions. They were no votes, even on own posts, so in the future I will count how many tasks you have completed. Last week's task was on the easier side so this week I tried to find something more interesting. Same as before you have a week to submit your solutions and no peeking before you have made your own! If you want to participate that is Small clarification on the level of the problem: the olympiad I am basing this challenge on (and probably some of the future ones) is meant for highschool students, grades 1012, so it's not something super hardcore Edit: small clarification of the challenge details. Weekly Challenge problem #2 [level: olympiad]You have two whole numbers k and s (1 <= k <= 10, 1 <= s <= 100). Find the biggest and the smallest numbers so that each one of them:  is made up out of nonrepeating digits  has k digits  doesn't start with a 0  sum of it's digits is s If there are no numbers that satisfy these conditions then output "none" Examples: Input  Output  k = 4, s = 6  max = 3210, min = 1023  k = 2, s = 20  none  k = 2, s = 10  max = 91, min = 19  k = 2, s = 3  max = 30, min = 12  k = 7, s = 38  max = 9876530, min = 1256789  k = 3, s = 11  max = 920, min = 128  k = 6, s = 15  max = 543210, min = 102345  k = 5, s = 36  none  k = 5, s = 9  none 
Good luck! Previous week's challenge:libertybasiccom.proboards.com/thread/1061/weeklylibertybasicchallenge1Hall of Fame (solutions submitted):  tenochtitlanuk  1   timur77  1   Rod  1   svajoklis  1 



Post by Rod on May 13, 2020 8:23:17 GMT 5
dim digit(9) for n= 0 to 9 digit(n)=n next
k=4 s=6
for o=0 to 9 for m=0 to 9 d=mo+1 p=0 for n=o to m found(p)=digit(n) p=p+1 'print digit(n);" "; t=t+digit(n) next 'print ,d,t if d=k and t=s then found=1 print "Found it" sort found(,d1,0 print "Max "; for x=0 to d1 print found(x); next print , Print "Min "; sort found(,0,d1 if found(0)=0 then found(0)=found(1) : found(1)=0 for x=0 to d1 print found(x); next end if t=0 next next if found=0 then print "Not Found"



Post by svajoklis on May 13, 2020 8:35:58 GMT 5
Had a run of your program, with k = 2 and s = 10 the answer should be 91 and 19, but your program outputs "not found" I think I will update the rules a bit for the next challenge so that the program has to read data from data statements that are at the top of the program, then have a rem/comment separator, so you could run the program without really looking at the solution to just check it. Before counting the results I will also try to create a test suite that I will run through each submission to check how 'correct' it was. I will of course post the suite and results together with the next challenge and will probably reward points based on how many of the test suite items the program calculated correctly, so 75% would be 0.75 points, 100% is 1 point.


timur77
Junior Member
Someday I will tell my grandsons that I am older than the Internet. And it will blow their brain.
Posts: 62

Post by timur77 on May 14, 2020 14:16:04 GMT 5
I solved the problem in two ways. The first way to break, a sequential search with filtering elements, for large values, searches for a long time. But it works. The second method is combinatorial, it is many times faster.
Tested programs with the following values: k=7 s=38 maxx=9876530 minn=1256789
k=3 s=11 maxx=920 minn=128
k=6 s=15 maxx=543210 minn=102345
k=5 s=36 none
k=5 s=9 none
№1
k=11 while (k<1 or k>10) input "k=";k wend
s=101 while (s<1 or s>100) input "s=";s wend '=========== maxxp=9876543210 mod 10^k smax=0 for e=1 to k smax=smax+Val(mid$(str$(maxxp),e,1)) next e if smax>s then print "none0":end '=========== maxx=int(9876543210 / 10^(10k)) '=========== smax=0 for e=1 to k smax=smax+Val(mid$(str$(maxx),e,1)) next e if smax<s then print "none1":end '      [L1] '      for i=1 to k pp$=mid$(str$(maxx),i,1) ppr=0 for a=1 to k if pp$=mid$(str$(maxx),a,1) then ppr=ppr+1 if ppr>1 then maxx=maxxmaxx mod 10^(ka):EXIT FOR next a if ppr>1 then EXIT FOR next i if ppr>1 then goto [L2] '      smax=0 for e=1 to k smax=smax+Val(mid$(str$(maxx),e,1)) next e locate 1,3 print maxx if smax<>s then goto [L2] '      print "maxx=";maxx '=========== '=========== minn=int(1023456789 / 10^(10k)) '=========== smin=0 for e=1 to k smin=smin+Val(mid$(str$(minn),e,1)) next e if smin>s then print "none2":end [L3] '      for i=1 to k pp$=mid$(str$(minn),i,1) ppr=0 for a=1 to k if pp$=mid$(str$(minn),a,1) then ppr=ppr+1 if ppr>1 then minn=minn+10^(ka)minn mod 10^(ka)1:EXIT FOR next a if ppr>1 then EXIT FOR next i if ppr>1 then goto [L4] '      smin=0 for e=1 to k smin=smin+Val(mid$(str$(minn),e,1)) next e locate 1,5 print minn if smin<>s then goto [L4] '      print "minn=";minn end '=========== [L2] if maxx>10^(k1) then maxx=maxx1 goto [L1] else print "none3" end if end '=========== [L4] if minn<10^(k+1) then minn=minn+1 goto [L3] else print "none4" end if end
№2
k=11 while (k<1 or k>10) input "k=";k wend
s=101 while (s<1 or s>100) input "s=";s wend '=================================== Dim sv(11) for i=1 to 10 sv(i)=1 next i
Dim maxx(11) data 9,8,7,6,5,4,3,2,1,0 for i=1 to 10 read buf maxx(i)=buf next i
[L1] sk=0 for i=1 to 10 sk=sk+sv(i) next i if sk<>k and sk<>0 then [L2] sv(10)=sv(10)1 for i=9 to 1 step (1) if sv(i+1)<0 then sv(i)=sv(i)1:sv(i+1)=1 next i if sv(1)=(1) then sv(1)=1 goto [L1] end if
ss=0 for i=1 to 10 ss=ss+maxx(i)*sv(i) next i if ss<>s and sk<>0 then goto [L2]
if sk=0 then print "none":end
print "maxx="; for i=1 to 10 if sv(i)=1 then print maxx(i); next i print "" '================================= for i=1 to 10 sv(i)=1 next i
Dim minn(11) data 1,0,2,3,4,5,6,7,8,9 for i=1 to 10 read buf minn(i)=buf next i
[L3] sk=0 for i=1 to 10 sk=sk+sv(i) next i if sk<>k and sk<>0 then [L4] sv(1)=sv(1)1 for i=2 to 10 if sv(i1)<0 then sv(i)=sv(i)1:sv(i1)=1 next i if sv(10)=(1) then sv(10)=1 goto [L3] end if
ss=0 for i=1 to 10 ss=ss+minn(i)*sv(i) next i if ss<>s and sk<>0 then goto [L4]
ei=0 ai=0 for i=1 to 10 if sv(i)>0 and minn(i)=1 then ei=1 if sv(i)>0 and minn(i)=0 then ai=1 next i if ei=0 and ai=1 then goto [L4]
if sk=0 then print "none":end
print "minn="; for i=1 to 10 if sv(i)=1 then print minn(i); next i end



Post by tenochtitlanuk on May 14, 2020 15:09:15 GMT 5
I thought much the same ways. Especially the need to think and optimise... Once I knew it worked for the original two examples, I did a kind of Monte Carlo method generating k and s at random but in range. Immediately showed how slow ten digits could get! It's quite fun to watch for the smaller k values, but for 5 or more digits gets slow.....
EDIT (updated code) Typical grabbed output.. Testing 4 digit numbers, between 1023 and 9876 whose digits sum to 6 1023 is OK for sum = 6 3210 is OK for sum = 6 Found
Testing 2 digit numbers, between 10 and 98 whose digits sum to 20 None
Testing 2 digit numbers, between 10 and 98 whose digits sum to 10 19 is OK for sum = 10 91 is OK for sum = 10 Found
Testing 2 digit numbers, between 10 and 98 whose digits sum to 3 12 is OK for sum = 3 30 is OK for sum = 3 Found
Testing 7 digit numbers, between 1023456 and 9876543 whose digits sum to 38 1256789 is OK for sum = 38 9876530 is OK for sum = 38 Found
Testing 3 digit numbers, between 102 and 987 whose digits sum to 11 128 is OK for sum = 11 920 is OK for sum = 11 Found
Testing 6 digit numbers, between 102345 and 987654 whose digits sum to 15 102345 is OK for sum = 15 543210 is OK for sum = 15 Found
Testing 5 digit numbers, between 10234 and 98765 whose digits sum to 36 None
Testing 5 digit numbers, between 10234 and 98765 whose digits sum to 9 None
As before I append my code lower on this page!
' Weekly Challenge problem #2
' You have two whole numbers k and s ( 1 <= k <= 10, 1 <= s <= 100).
' Find the biggest and the smallest numbers so that: '  each one is made up out of nonrepeating digits '  each one has k digits '  each one doesn't start with a 0 '  the sum of digits is s
' If there are no numbers that satisfy these conditions then output "none" ' k s data 4, 6 'max = 3210, min = 1023 data 2, 20 'none data 2, 10 'max = 91, min = 19 data 2, 3 'max = 30, min = 12 data 7, 38 'max = 9876530, min = 1256789 data 3, 11 'max = 920, min = 128 data 6, 15 'max = 543210, min = 102345 data 5, 36 'none data 5, 9 'none
open "anaysis2.txt" for output as #fOut
global digit$, k, s, finished, result$ digFwd$ ="0123456789" digRev$ ="9876543210" order$ ="1023456789" ' smallest number is sum of leftmost k characters of this.
for d =1 to 9 read k, s result$ ="None"
biggestPoss =val( left$( digRev$, k)) lowestPoss =val( left$( order$, k)) #fOut " Testing "; k; " digit numbers, between ";lowestPoss; " and "; biggestPoss; " whose digits sum to "; s print " Testing "; k; " digit numbers, between ";lowestPoss; " and "; biggestPoss; " whose digits sum to "; s
for n =lowestPoss to biggestPoss call test n if finished =1 then exit for next n
print result$
next d
wait
sub quit h$ close #fOut end sub
sub test n ' testNumber finished =0 n$ =str$( n) available$ =digit$ for p =1 to len( n$) sum =sum +val( mid$( n$, p, 1)) next p if ( sum =s) and digitsDifferent( n$) =1 then #fOut n$; " is OK for sum = "; s: print n$; " is OK for sum = "; s: result$ ="Found"
'if ( sum >10^k) then finished =1': print "None." scan end sub
function digitsDifferent( n$) digitsDifferent =1 for q =1 to len( n$) 1 currentDigit$ =mid$( n$, q, 1) if instr( mid$( n$, q +1), currentDigit$) then digitsDifferent =0 next q end function



Post by svajoklis on May 14, 2020 15:34:29 GMT 5
Timur77 goes above and beyond, looks very good! I have taken the liberty (pun intended) of adding your test cases to the main task Usually there is a time and memory constraints on the solutions, so a brute force solution wouldn't even pass the "checking" stage in the olympiad. There are "hidden" (you don't get to see the input data) test cases are with biggest limits possible, and the time constraints are such, that a bruteforce solution would simply take too long. Hell, you could generate Mona Liza if you had enough time to brute force each pixel for a decently sized image I wouldn't say the solution would deserve 0 points, but at the same time I couldn't give it more than 0.1 since it completely bypasses the idea of the task



Post by svajoklis on May 18, 2020 16:44:45 GMT 5
I think the olympiad level tasks are a bit more engaging, loved completing it. Broke out a lot of extra functions to make the code a bit more readable. It's a recursive solution that tries to return back up the stack whenever it sees that it hasn't gone down a good path. ' parameters ' k, s data 7, 38
' you can either run the solution to data values, or a test suite by uncommenting corresponding sub call read k, s call solution k, s ' call doTests
end
sub solution k, s empty$ = "" for i = 1 to k : empty$ = empty$ + "0" : next i
max$ = doBiggest$(k, s, empty$, 1, 1) if max$ <> "none" then min$ = doSmallest$(k, s, empty$, 1, 1) print "max = "; max$; ", min = "; min$ else print "none" end if end sub
function doNumber$ (digits$, k, s, number$, processedNumber, nextIndex) if processedNumber <= len(number$) and nextIndex <= len(digits$) and sumDigits(number$) <= s then for a = nextIndex to len(digits$) newNumber$ = setDigit$(number$, processedNumber, getDigit$(digits$, a)) if getDigit$(newNumber$, 1) <> "0" then ret$ = doNumber$(digits$, k, s, newNumber$, processedNumber + 1, a + 1) if len(ret$) > 0 then doNumber$ = ret$ exit for end if end if next a end if
if sumDigits(number$) = s and processedNumber > len(number$) then doNumber$ = number$ end if
' nothing came back, return "none" if len(doNumber$) = 0 and processedNumber = 1 then doNumber$ = "none" end if end function
function doBiggest$ (k, s, number$, processedNumber, nextIndex) digits$ = "9876543210" doBiggest$ = doNumber$(digits$, k, s, number$, processedNumber, nextIndex) end function
function doSmallest$ (k, s, number$, processedNumber, nextIndex) digits$ = "1023456789" doSmallest$ = doNumber$(digits$, k, s, number$, processedNumber, nextIndex) end function
sub test k, s, expected$ empty$ = "" for i = 1 to k : empty$ = empty$ + "0" : next i out$ = "" max$ = doBiggest$ (k, s, empty$, 1, 1) if max$ <> "none" then min$ = doSmallest$ (k, s, empty$, 1, 0) out$ = "max = "; max$; ", min = "; min$ else out$ = "none" end if
print out$ print expected$ if out$ = expected$ then print "OK!" else print "fail" end if print end sub
sub doTests call test 4, 6, "max = 3210, min = 1023" call test 2, 20, "none" call test 2, 10, "max = 91, min = 19" call test 2, 3, "max = 30, min = 12" call test 7, 38, "max = 9876530, min = 1256789" call test 3, 11, "max = 920, min = 128" call test 6, 15, "max = 543210, min = 102345" call test 5, 36, "none" call test 5, 9, "none" end sub
' util functions
function sumDigits (string$) sumDigits = 0 for i = 1 to len(string$) sumDigits = sumDigits + val(mid$(string$, i, 1)) next i end function
function getDigit$ (string$, index) getDigit$ = mid$(string$, index, 1) end function
function setDigit$ (string$, index, character$) setDigit$ = mid$(string$, 1, index  1) + character$ + mid$(string$, index + 1) end function
Oh wow, it does seem we all went to quite similar solutions It's interesting to see everyone's different coding styles like that

