about summary refs log tree commit diff
path: root/users/sterni/exercises/aoc/2021/solutions.bqn
blob: 725dffc81f625dbdde1f7c2fcd86a13a00a51c8c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
#!/usr/bin/env BQN

#
# Utilities
#

IsAsciiNum ← ('0'⊸≤∧≤⟜'9')

ReadInt ← {(𝕨⊸×+⊣)´∘⌽-⟜'0'𝕩} # stolen from leah2
ReadDec ← 10⊸ReadInt

ReadInput ← {•file.Lines ∾ •path‿"/input/day"‿(•Fmt 𝕩)}

SplitOn ← ((⊢ (-1˙)⍟⊣¨ +`)∘=⊔⊢)

_fix ← {𝕩 𝕊∘⊢⍟≢ 𝔽 𝕩}

#
# 2021-12-01
#

# part 1

day1ExampleInput ← 199‿200‿208‿210‿200‿207‿240‿269‿260‿263
day1Input ← ReadDec¨ReadInput 1

# NB: Because distance from the ground is never smaller than zero, it's
# no problem that nudge inserts a zero at the end of the right list
PositiveDeltaCount ← +´∘(⊢<«)+˝˘∘↕

! 7 = 1 PositiveDeltaCount day1ExampleInput

•Out "Day 1.1: "∾•Fmt 1 PositiveDeltaCount day1Input

# part 2

! 5 = 3 PositiveDeltaCount day1ExampleInput

•Out "Day 1.2: "∾•Fmt 3 PositiveDeltaCount day1Input

#
# 2021-12-02
#

# part 1

day2ExampleInput ← ⟨
  "forward 5",
  "down 5",
  "forward 8",
  "up 3",
  "down 8",
  "forward 2",

day2Input ← ReadInput 2

ParseSubmarineCommand ← (((↕2)⊸((((-1)⊸⋆)∘(2⊸|))×(=⟜(⌊∘(÷⟜2))))∘("duf"⊸⊐)∘⊑)×ReadDec∘(IsAsciiNum/⊢))

SubmarineDestProduct ← {×´+´ParseSubmarineCommand¨𝕩}

! 150 = SubmarineDestProduct day2ExampleInput

•Out "Day 2.1: "∾•Fmt SubmarineDestProduct day2Input

# part 2

SubmarineAimedDestProduct ← {
  ×´+´((×´)∘(1⊸↓)≍(1⊸⊑))¨ (<0‿0‿0) (⊢∾((⊑∘⌽⊣)+(⊑⊢)))` ParseSubmarineCommand¨𝕩
}

! 900 = SubmarineAimedDestProduct day2ExampleInput

•Out "Day 2.2: "∾•Fmt SubmarineAimedDestProduct day2Input

#
# 2021-12-03
#

BinTable ← '0'-˜>

day3ExampleInput ← BinTable ⟨
  "00100",
  "11110",
  "10110",
  "10111",
  "10101",
  "01111",
  "00111",
  "11100",
  "10000",
  "11001",
  "00010",
  "01010",

day3Input ← BinTable ReadInput 3

DeBinList ← ((2⊸×)+⊣)´⌽
_tableAggr ← {((÷⟜2)∘(/⟜⥊)´∘⌽∘≢𝔽(+˝))𝕩}
GammaRate ← < _tableAggr

! 22 = DeBinList GammaRate day3ExampleInput
! 9  = DeBinList ¬GammaRate day3ExampleInput

•Out "Day 3.1: "∾•Fmt (¬×○DeBinList⊢) GammaRate day3Input

_lifeSupportRating ← {
  # Need to rename the arguments, otherwise the ternary expr becomes a function
  bitPos ← 𝕨
  Cmp ← 𝔽

  crit ← Cmp _tableAggr 𝕩
  matchPos ← bitPos ⊑˘ crit ((⥊˜⟜≢)=⊢) 𝕩
  match ← matchPos/𝕩
  {1=≠match?⊏match;(bitPos+1) Cmp _lifeSupportRating match}
}

OxygenGeneratorRating ← DeBinList 0 ≤_lifeSupportRating ⊢
CO2ScrubberRating ← DebinList 0 >_lifeSupportRating ⊢

! 23 = OxygenGeneratorRating day3ExampleInput
! 10 = CO2ScrubberRating day3ExampleInput

•Out "Day 3.2: "∾•Fmt (OxygenGeneratorRating×CO2ScrubberRating) day3Input

#
# 2021-12-07
#

# part 1

day6ExampleInput ← ⟨16,1,2,0,4,2,7,1,2,14⟩
day6Input ← ReadDec¨ ','  SplitOn ⊑ReadInput 6

PossiblePositions ← (⌊´+⟜(↕1⊸+)⌈´)
FuelConsumption ← +˝∘|∘(-⌜)
_lowestFuelPossible ← {⌊´∘(𝔽⟜PossiblePositions)˜ 𝕩}

! 37 = FuelConsumption _lowestFuelPossible day6ExampleInput

•Out "Day 7.1: "∾•Fmt FuelConsumption _lowestFuelPossible day6Input

# part 2

TriNum ← 1⊸+×÷⟜2

FuelConsumption2 ← +˝∘(TriNum¨)∘|∘(-⌜)

! 168 = FuelConsumption2 _lowestFuelPossible day6ExampleInput

•Out "Day 7.2: "∾•Fmt FuelConsumption2 _lowestFuelPossible day6Input

#
# 2021-12-09
#

# part 1

ParseHeightMap ← ((≠≍(≠⊑))⥊∾)∘-⟜'0'

day9ExampleInput ← ParseHeightMap ⟨
  "2199943210",
  "3987894921",
  "9856789892",
  "8767896789",
  "9899965678"
day9Input ← ParseHeightMap ReadInput 9

Rotate ← (⍉⌽)∘⊢⍟⊣ # counter clockwise
LowPoints ← {∧´𝕩⊸(⊣<((-⊢) Rotate ∞⊸»˘∘Rotate˜))¨ ↕4}

RiskLevelSum ← (+´⥊)∘(1⊸+×LowPoints)

! 15 = RiskLevelSum day9ExampleInput

•Out "Day 9.1: "∾•Fmt RiskLevelSum day9Input

# part 2

NumberBasins ← ((1⊸+⊒⌾⥊)×⊢)∘LowPoints
Basins ← {𝕩⊸((<⟜9⊣)∧(«⌈»⌈«˘⌈»˘⌈⊢)∘⊢) _fix NumberBasins 𝕩}
LargestBasinsProduct ← {×´ 3↑ ∨ 1↓ ≠¨ ⊔⥊Basins 𝕩}

! 1134 = LargestBasinsProduct day9ExampleInput

•Out "Day 9.2: "∾•Fmt LargestBasinsProduct day9Input