On second though, Howard, are you sure your code is ok? I mean, you work with only 16 permutations of the possible 24!! Try runing under my improved test script (streamlined the output, and fixed some bugs). Also, and since one of the solutions that your code fails to find is one that has nothing to do with the permutations, there's bound to be some major error in there other than the missing permutations... Try your code with the 5555 set and check it out...

code:
BREAK ON
 
Global $Target, $Valid
 
$Target      = 24
$ErrorMargin = 0.0001
$Valid = "003800460128013601370138013901450146014701480155015602260234"
       + "023602380239024402460248025702580266026802690288033403350337"
       + "033803390344034603480349035803590366036703680378038803890445"
       + "044604470448045604660467046804690478048805660569058806890699"
       + "078908881118112611271128112911341135113611371138113911441145"
       + "114611471148114911551156115711581166116811691188122412251226"
       + "122712281229123312341235123612371238123912441245124612471248"
       + "124912551256125712581259126612671268126912771278127912881289"
       + "133313341335133613371338133913441345134613471348134913561357"
       + "135813591366136713681369137713781379138813891399144414451446"
       + "144714481449145514561457145814591466146714681469147714781479"
       + "148814891555155615591566156715681569157815791588158915991666"
       + "166816691679168816891699177917881789179918881889222322242225"
       + "222722282229223322342235223622372238223922442245224622472248"
       + "224922552256225722582259226622672268226922772278228822892333"
       + "233523362337233823392344234523462347234823492355235623572358"
       + "235923662367236823692377237823792388238923992444244524462447"
       + "244824492455245624572458245924662467246824692477247824792488"
       + "248924992557255825592566256725682569257725782579258825892666"
       + "266726682669267826792688268926992778278827892888288928993333"
       + "333433353336333733383339334433453346334733483349335533563357"
       + "335933663367336833693377337833793389339934443445344634473448"
       + "344934553456345734583459346634683469347734783479348934993556"
       + "355735583559356635673568356935783579358835893599366636673668"
       + "366936773678367936883689369937773778377937883789379938883889"
       + "389939994444444544464447444844494455445644574458446844694477"
       + "447844794488448945554556455745584559456645674568456945774578"
       + "457945884589459946664667466846694677467846794688468946994777"
       + "477847884789479948884889489955555556555955665567556855775578"
       + "558855895599566656675668566956775678567956885689569957795788"
       + "578958885889666666686669667966886689678967996888688968997889"
       + "3388"
 
$rc=SETOPTION('Explicit','ON')
$rc=SETOPTION('NoVarsInString','ON')
$rc=SRND(@MSECS)
 
? 'Game24 v 1.1 KiXtart Golf running under KiXtart v'@KIX
? ''
Dim $i
 
test24(1,2,3,4,1)
test24(2,2,6,8,1)
test24(4,4,6,6,2)
test24(3,3,8,8,1)
for $i = 1 to 20
  test24(RND(9),RND(9),RND(9),RND(9),3)
next
test24(3,4,7,7,1)
test24(1,2,8,9,1)
test24(3,3,7,7,1)
? ""
 
; Inputs: $i1..$i4 => 4 numbers to pass to game24
; $behaviour = 1 -> Expected result
; $behaviour = 2 -> Expected to fail
; $behaviour = 3 -> Don't know (random)
function test24($i1,$i2,$i3,$i4,$behaviour)
  DIM $rc, $out, $result, $error, $str, $i, $found, $temp, $nums[4], $numbers
  
  $str = 'In: '+$i1+$i2+$i3+$i4+'; Out: '
  $out=Game24($i1,$i2,$i3,$i4)
  if instr($out,".") == 0
    $i = 1
    while $i <= Len($out)
      if ( SubStr($out,$i,1) >= '0' ) and ( SubStr($out,$i,1) <= '9' )
        $out = Left($out,$i) + '.0' + SubStr($out,$i+1)
        $i = $i + 2;
      endif;
      $i = $i + 1;
    loop
  endif
  $error=Execute("$$result=("+$out+")")
  $result=Trim($result)
  Dim $tmpStr
  $tmpStr = $out
  while (len($tmpStr)<22)
    $tmpStr = $tmpStr + " "
  loop
  $str = $str + left($tmpStr, 22) + " = " + $result
  if (len($result)<2)
    $str = $str+"  "
  endif
  if ( $behaviour = 3 )
    ; sort numbers used, so as to check array of possible solutions
    $nums[0] = $i1
    $nums[1] = $i2
    $nums[2] = $i3
    $nums[3] = $i4
    do
      $found = 0
      for $i = 0 to 2
        if $nums[$i] > $nums[$i+1]
          $found      = 1
          $temp       = $nums[$i+1]
          $nums[$i+1] = $nums[$i]
          $nums[$i]   = $temp
        endif
      next
    until $found == 0
    $numbers = "" + $nums[0] + $nums[1] + $nums[2] + $nums[3]
    ; check for presence in array
    $found = 0
    $i = 1
    while ( $found == 0 ) and ( $i < Len($Valid) )
      if ( SubStr( $Valid, $i, 4 ) == $numbers )
        $found = 1
      endif
      $i = $i + 4
    loop
    if $found and ( ($result>=$Target-$ErrorMargin) and 
         ($result<=$Target+$ErrorMargin) )
      $str = $str + " => Correct!!"
    else 
      if not $found and $result=""
        $str = $str + " => Correct!!"
      else
        $str = $str + " => WRONG!!"
      endif
    endif
  else
    if ( ($behaviour=1) and ($result>=$Target-$ErrorMargin) and 
         ($result<=$Target+$ErrorMargin) )
      or ( ($behaviour=2) and ($result='') )
      $str = $str + " => Correct!!"
    else
      $str = $str + " => WRONG!!"
    endif
  endif
  ? $str
endfunction
 
Dim $shellcommand
$shellcommand='kix32 Kixgolf3.kix $f='+@scriptname
? $shellcommand
Shell $shellcommand
 
; Operators: 64 combinations
; +++  ++-  ++*  ++/  +-+  +--  +-*  +-/  +*+  +*-  +**  +*/  +/+  +/-  +/*  +//
; -++  -+-  -+*  -+/  --+  ---  --*  --/  -*+  -*-  -**  -*/  -/+  -/-  -/*  -//
; *++  *+-  *+*  *+/  *-+  *--  *-*  *-/  **+  **-  ***  **/  */+  */-  */*  *//
; /++  /+-  /+*  /+/  /-+  /--  /-*  /-/  /*+  /*-  /**  /*/  //+  //-  //*  ///
 
; Digits: 24 permutations
; abcd  abdc  acbd  acdb  adbc  adcb
; bacd  badc  bcad  bcda  bdac  bdca
; cabd  cadb  cbad  cbda  cdab  cdba
; dabc  dacb  dbac  dbca  dcab  dcba
 
; Parentheses: 4 combinations
; 123456789 12345 (15 chars)
;  a. b . c .d
; (a. b).(c .d)
;  a.(b . c .d)
; (a. b . c).d
 
;    0 need (ab)cd
;    0 need a(bc)d
;    0 need ab(cd)
; ------------------
;    1 need (abc)d
; ------------------
;    3 need a(bcd)
;   13 need (ab)(cd)
; ------------------
;  131 need at least one '+'
;  174 need at least one '-'
;  306 need at least one '*'
;   36 need at least one '/' 
;!
function game24($a,$b,$c,$d)
endfunction  
 
;!
;!
{edit} Added an if to only add (.0)s if there's no '.' in the returned string. {/edit}

[ 23. September 2002, 20:40: Message edited by: Fernando Madruga ]
_________________________
Later,   [b]Mad[/b]ruga