Truncatable primes: Difference between revisions

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Midaz

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Revision as of 06:31, 28 May 2023 (view source) Elfish (talk \| contribs) No edit summary ← Older edit		Latest revision as of 20:45, 25 June 2024 (view source) Midaz (talk \| contribs) (Added Uiua solution)
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Line 996: </pre> =={{header\|EasyLang}}== <syntaxhighlight> fastfunc isprim num . if num < 2 return 0 . i = 2 while i <= sqrt num if num mod i = 0 return 0 . i += 1 . return 1 . func isright h . while h > 0 if isprim h = 0 return 0 . h = h div 10 . return 1 . func isleft h . d = pow 10 (floor log10 h) while h > 0 if isprim h = 0 return 0 . if h div d = 0 return 0 . h = h mod d d /= 10 . return 1 . p = 999999 while isleft p = 0 p -= 2 . print p p = 999999 while isright p = 0 p -= 2 . print p </syntaxhighlight> {{out}} <pre> 998443 739399 </pre> =={{header\|EchoLisp}}== Line 1,184 ⟶ 1,240: =={{header\|Elena}}== ELENA 56.0x : <syntaxhighlight lang="elena">import extensions; Line 1,197 ⟶ 1,253: if (n < 2) { ^ false }; if (n < 4) { ^ true }; if (n.mod:(2) == 0) { ^ false }; if (n < 9) { ^ true }; if (n.mod:(3) == 0) { ^ false }; int r := n.sqrt(); Line 3,270 ⟶ 3,326: Largest left truncatable prime : 998443 Largest right truncatable prime : 739399 </pre> =={{header\|RPL}}== {{works with\|HP\|49}} ≪ → trunc ≪ <span style="color:red">1000000</span> '''DO''' '''DO''' PREVPRIME '''UNTIL''' DUP →STR <span style="color:red">"0"</span> POS NOT '''END''' DUP <span style="color:red">1</span> SF '''DO''' trunc EVAL '''IF''' DUP ISPRIME? NOT '''THEN''' <span style="color:red">1</span> CF '''END''' '''UNTIL''' DUP <span style="color:red">9</span> ≤ <span style="color:red">1</span> FC? OR '''END''' DROP '''UNTIL''' <span style="color:red">1</span> FS? '''END''' ≫ ≫ '<span style="color:blue">XTRUNC</span>' STO ≪ →STR TAIL STR→ ≫ <span style="color:blue">XTRUNC</span> ≪ <span style="color:red">10</span> / IP ≫ <span style="color:blue">XTRUNC</span> {{out}} <pre> 2: 998443 1: 739399 </pre> Line 3,584 ⟶ 3,663: searching for largest right-truncatable prime FOUND:739399 </pre> =={{header\|Uiua}}== <syntaxhighlight lang="uiua"> Mag ← 6 MaxP ← ⁿ:10⌊÷2Mag # Pre-calculate primes up to root of largest n Primes ← ⇌◌⍢(▽≠0◿⊢..⟜(⊂⊢)\|>0⧻.):[]⊂2↘1+1×2⇡⌊÷2 MaxP # Build primes IsPrime ← ⨬(/↧≡(≠0◿)\|1)∊:,,Primes RAdd ← ♭⊞(+×10):1_3_7_9 # Add suffixes LAdd ← ♭⊞+×ⁿ:10⌈ₙ10⊢,+1⇡9 # Add prefixes LastTP! ← ⊡¯1⍥(▽⊸≡IsPrime^!)-1Mag 2_3_5_7 # Build and filter $"Right truncating: _"LastTP!RAdd $"Left truncating: _"LastTP!LAdd </syntaxhighlight> {{out}} <pre> "Right truncating: 739399" "Left truncating: 998443" </pre> Line 3,668 ⟶ 3,766: {{libheader\|Wren-fmt}} {{libheader\|Wren-math}} <syntaxhighlight lang="~~ecmascript~~wren">import "./fmt" for Fmt import "./math" for Int var limit = 999999