From 3194222de4a191baf4062a78a1da735be73da7d1 Mon Sep 17 00:00:00 2001 From: Brian Chu Date: Sat, 8 Jan 2022 10:41:47 -0800 Subject: solution for day 19 --- day19.fsx | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 day19.fsx (limited to 'day19.fsx') diff --git a/day19.fsx b/day19.fsx new file mode 100644 index 0000000..f30c140 --- /dev/null +++ b/day19.fsx @@ -0,0 +1,15 @@ +open System + +let rec josephus = + function + | 1 -> 1 + | x -> (if x % 2 <> 0 then 1 else -1) + 2 * josephus (x / 2) + +let josephus' (target: int): int = + let pow = Math.Pow(3, Math.Floor(Math.Log(target, 3))) |> int + if pow = target then pow + else if pow >= target / 2 then target - pow + else pow + (2 * (target - 2 * pow)) + +josephus 3017957 |> printfn "%d" +josephus' 3017957 |> printfn "%d" \ No newline at end of file -- cgit 1.4.1-2-gfad0 e='main'>main Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.Kartik K. Agaram <vc@akkartik.com>
about summary refs log tree commit diff stats
path: root/110stop.subx
blob: f6cb6fae114e0e820e5800349a28fdfbd77a423b (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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214