Kaprekar numbers: Difference between revisions

</pre>

=={{header|RPL}}==

{{trans|Python}}

{{works with|Halcyon Calc|4.2.7}}

{| class="wikitable"

! RPL code

! Comment

|-

|

≪ DUP SQ →STR DUP SIZE → n n2 n2s

≪ 1 CF 1 n2s 1 - '''FOR''' j

'''IF''' n2 j 1 + n2s SUB STR→ '''THEN'''

LAST n2 1 j SUB STR→

'''IF''' DUP2 + n ==

'''THEN''' 1 SF n2s 'j' STO '''ELSE''' DROP2 '''END'''

'''END'''

'''NEXT'''

'''IF''' 1 FS?

'''THEN''' n →STR "=" + SWAP →STR + "+" + SWAP →STR +

'''ELSE''' "" '''END'''

≫ ≫ ''''KPREK'''' STO

≪ { 1 } 9 10000 '''FOR''' n 0 1 '''FOR''' k

n k + '''KPREK''' IF DUP "" ≠ '''THEN''' + '''ELSE''' DROP '''END'''

'''NEXT''' 9 '''STEP'''

≫ ''''TASK'''' STO

|

'''KPREK''' ''( n -- string )''

Examine all the possible a|b cuts of n²

if b is not zero

restore b in stack and get a

if a + b == n

then exit loop

if a and b found

then edit result

else return an empty string

'''TASK''': Loop ad examine

only numbers mod 9 = 0 or 1 (see Maple section)

|}

{{out}}

<pre>

1: { 1 "9=8+1" "45=20+25" "55=30+25" "99=98+1" "297=88+209" "703=494+209" "999=998+1" "2223=494+1729" "2728=744+1984" "4879=238+4641" "4950=2450+2500" "5050=2550+2500" "5292=28+5264" "7272=5288+1984" "7777=6048+1729" "9999=9998+1" }