Left factorials: Difference between revisions
add RPL
(add RPL) |
|||
Line 3,240:
next
</syntaxhighlight>
=={{header|RPL}}==
For small values of n, we can use the native format for integers:
≪ '''IF''' DUP '''THEN''' 0 1 ROT 1 - '''FOR''' k k FACT + '''NEXT END''' ≫ ‘<span style="color:blue">LFACT</span>’ STO
≪ { } 0 10 '''FOR''' n n <span style="color:blue">LFACT</span> + '''NEXT''' ≫ EVAL
'''Output:'''
1: { 0 1 2 4 10 34 154 874 5914 46234 409114 }
For 20 through 110 (inclusive) by tens, we need a kind of BigInt library if using a RPL version of the previous century. <code>ADDbig</code> and <code>MULbig</code> are defined at [[Long multiplication#RPL|Long multiplication]].
Calculation is optimized by using the recursive formula: <code>!(n+1) = !n * n + 1</code>
≪ "1" SWAP
'''WHILE''' DUP 1 > '''REPEAT'''
1 - DUP →STR <span style="color:blue">ROTMULbig</span> "1" <span style="color:blue"><span style="color:blue">ADDbig</span></span> SWAP
'''END''' DROP
≫ ‘<span style="color:blue">LFACTbig</span>’ STO
≪ 20 110 '''FOR''' n n <span style="color:blue">LFACTbig</span> 10 '''STEP''' ≫ EVAL
{{out}}
<pre>
10: "128425485935180314"
9: "9157958657951075573395300940314"
8: "20935051082417771847631371547939998232420940314"
7: "620960027832821612639424806694551108812720525606160920420940314"
6: "141074930726669571000530822087000522211656242116439949000980378746128920420940314"
5: "173639511802987526699717162409282876065556519849603157850853034644815111221599509216528920420940314"
4: "906089587987695346534516804650290637694024830011956365184327674619752094289696314882008531991840922336528920420940314"
3: "16695570072624210767034167688394623360733515163575864136345910335924039962404869510225723072235842668787507993136908442336528920420940314"
2: "942786239765826579160595268206839381354754349601050974345395410407078230249590414458830117442618180732911203520208889371641659121356556442336528920420940314"
1: "145722981061585297004706728001906071948635199234860720988658042536179281328615541936083296163475394237524337422204397431927131629058103519228197429698252556442336528920420940314"
</pre>
=={{header|Ruby}}==
| |||