2024 day 1

becojo · Dec 1, 2024 · b67b2cc · b67b2cc
1 parent 5f5f5b4
commit b67b2cc
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diff --git a/2024/.gitignore b/2024/.gitignore
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+/[0-9]
+/[0-9][0-9]
diff --git a/2024/1-test b/2024/1-test
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+3   4
+4   3
+2   5
+1   3
+3   9
+3   3
diff --git a/2024/1.rb b/2024/1.rb
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+input = ARGF.read.lines
+ax = []
+bx = []
+
+input.each do |line|
+    a, b = line.split.map(&:to_i)
+    ax << a
+    bx << b
+end
+
+ax.sort!
+bx.sort!
+
+part1 = ax.zip(bx).map do |(a, b)|
+    (b - a).abs
+end.sum
+
+puts part1
+
+bf = bx.group_by(&:itself).transform_values(&:size)
+part2 = ax.map do |a|
+    a * bf.fetch(a, 0)
+end.sum
+
+puts part2
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+4
+3
+5
+3
+9
+3