Day 8

[advent-of-code-2021.git] / day08 / notes.txt

diff --git a/day08/notes.txt b/day08/notes.txt
new file mode 100644 (file)
index 0000000..5016bb9
--- /dev/null
+++ b/day08/notes.txt
@@ -0,0 +1,109 @@
+0: 6 segments lit: abcefg
+  aaaa
+ b    c
+ b    c
+  ....
+ e    f
+ e    f
+  gggg
+
+1: 2 segments lit: cf
+  ....
+ .    c
+ .    c
+  ....
+ .    f
+ .    f
+  ....
+
+2: 5 segments lit: acdeg
+  aaaa
+ .    c
+ .    c
+  dddd
+ e    .
+ e    .
+  gggg
+
+3: 5 segments lit: acdfg -> 7+dg
+  aaaa
+ .    c
+ .    c
+  dddd
+ .    f
+ .    f
+  gggg
+
+4: 4 segments lit: bcdf -> 1+bd
+  ....
+ b    c
+ b    c
+  dddd
+ .    f
+ .    f
+  ....
+
+5: 5 segments lit: abdfg
+  aaaa
+ b    .
+ b    .
+  dddd
+ .    f
+ .    f
+  gggg
+
+6: 6 segments lit: abdefg
+  aaaa
+ b    .
+ b    .
+  dddd
+ e    f
+ e    f
+  gggg
+
+7: 3 segments lit: acf -> 1+a <-- this means we can work out a
+  aaaa
+ .    c
+ .    c
+  ....
+ .    f
+ .    f
+  ....
+
+8: 7 segments lit: abcdefg
+  aaaa
+ b    c
+ b    c
+  dddd
+ e    f
+ e    f
+  gggg
+
+9: 6 segments lit: abcdfg
+  aaaa
+ b    c
+ b    c
+  dddd
+ .    f
+ .    f
+  gggg
+
+0: abc efg -> 1 + 2 + 4 + 16 + 32 + 64       -> 119
+1:   c  f  -> 4 + 32                         -> 36
+2: a cde g -> 1 + 4 + 8 + 16 + 64            -> 93
+3: a cd fg -> 1 + 4 + 8 + 32 + 64            -> 109
+4:  bcd f  -> 2 + 4 + 8 + 32                 -> 46
+5: ab d fg -> 1 + 2 + 8 + 32 + 64            -> 107
+6: ab defg -> 1 + 2 + 8 + 16 + 32 + 64       -> 123
+7: a c  f  -> 1 + 4 + 32                     -> 37
+8: abcdefg -> 1 + 2 + 4 + 8 + 16 + 32 + 64   -> 127
+9: abcd fg -> 1 + 2 + 4 + 8 + 32 + 64        -> 111
+
+a: 8
+b: 6
+c: 8
+d: 7 - only one that's exactly a 7 count
+e: 4 - only one that's exactly a 4 count
+f: 9 - only one that's exactly a 9 count
+g: 7
+