---
title: "APL Competition 2022"
author: "Jeremy Howard"
date: "2022-07-05"
categories: [Dyalog, APL, Glyphs]
---
]box on -style=max -trains=tree -fns=on

'Hip' 'Hop'

↑ 'Hip' 'Hop'

⍴↑ 'Hip' 'Hop'

'Hip' 'Hop' 'Dance'

↑ 'Hip' 'Hop' 'Dance'

⍴↑ 'Hip' 'Hop' 'Dance'

(6 4) 5 3
↑ (6 4) 5 3

(1 2) 3 (4 5 6)
↑(1 2) 3 (4 5 6)

4 ↑ 'Pineapple'

12 ↑ 'Pineapple'

¯5 ↑ 'Pineapple'

⎕←mat←3 4⍴⍳12

2 ↑ mat

¯2 ↑ mat

5 ↑ mat

2 ¯3 ↑ mat

⎕←mat←3 4⍴⍳12

↓mat

⎕ ← mat ← 3 1⍴'Hip' 'Hop' 'Dance'

↓mat

4 ↓ 'Pineapple'

12 ↓ 'Pineapple'

¯5 ↓ 'Pineapple'

⎕←mat←3 4⍴⍳12

2 ↓ mat

2 ¯3 ↓ mat

a ← 'banana'

,⌸ a

a {⍺,+/⍵}⌸ ⍳6

a ,⌸ ⍳6

1 2 3

⍴1 2 3

⊂1 2 3

⍴⊂1 2 3

1(2 3)

⍴ 1(2 3)

1,⊂2 3

⊂ 1(2 3)

⍴⊂ 1(2 3)

⊂⊂ 1(2 3)

⊂1

1 2 3+⊂4 5 6

1 2 3+1

1 0 1 0 0 0 0⊂ 1 2 3 4 5 6 7

1 0 1 0 0 0 0⊂'HiEarth'

2 0 1 0 3 0 ⊂ 1 2 3 4 5 6

1 0 2 0 0 0 0⊂'HiEarth'

(⊆1) ≡ ⊂1

(⊆1 2 3) ≡ ⊂1 2 3

(⊆ 1 (1 2 3)) ≡ 1 (1 2 3)

⊆ 1 (1 2 3)

1 (1 2 3)

⊂ 1 (1 2 3)

1 1 1 0 1 1 1 0 1 1 1 1⊆'How are you?'

1 1 2 2 2 2 2⊆'HiEarth'

1 1 2 2 2 0 0⊆'HiEarth'

a←1 2

⊂a

a ≡ ⎕ ← ⊃⊂1 2

⊃ 'Word'

⊃ (1 (1 2) 3) 4

⊃ (1 2)(3 4 5)

3 ⊃ 'Word'

2 ⊃ (1 2)(3 4 5)

2 1 ⊃ (1 2)(3 4 5)

⎕←mat ← 2 3⍴⍳6

(⊂2 1) ⊃ 2 3⍴⍳6

G←2 3⍴('ABC' 1)('DEF' 2)('GHI' 3)('JKL' 4),('MNO' 5)('PQR' 6)
G

((⊂2 1),1) ⊃ G

⊢1

⊢'abc'

'abc'⊢1

1⊢'abc'

⊣'abc'

'abc'⊣1

1⊣'abc'

2 ⊥ 1 1 0 1   ⍝ binary decode

⍝ mixed radix: conversion of hours,
⍝ minutes and seconds to seconds:
24 60 60 ⊥ 2 46 40

(2×60×60) + (46×60) + 40

10 ⊥ 1 1 0 1   ⍝ decimal decode

10 ⊥ 3 4 1 6   ⍝ decimal decode

1j1⊥1 2 3 4

1⊥3 1 4 1 5 9

⎕←M←3 4⍴⍳12

1⊥M

10 10 10 10 10 ⊤ 3658   ⍝ decimal encode

10 10 10 ⊤ 3658   ⍝ truncated decimal encode

0 10 10 ⊤ 3658

2 2 2 2 ⊤ 7   ⍝ binary encode

2 2 ⊤ 7   ⍝ truncated binary encode

2 2 2 2 ⊤ 5 7 12   ⍝ binary encode

⍝ mixed radix: encode of 10000 seconds
⍝ to hours, minutes and seconds:
24 60 60 ⊤ 10000

(÷3)+(*3)

(÷+*)3

(+/÷≢) 2 5 8 9

mean ← +/÷≢

mean 2 5 8 9

' '≠'How are you?'

' '⊢'How are you?'

(' '≠'How are you?') ⊆ (' '⊢'How are you?')

' '(≠⊆⊢)'How are you?'

split ← {(⍺≠⍵) ⊆ (⍺⊢⍵)}

' ' split 'How are you?'