day 03: Transpose the rows

petertseng · petertseng · commit 4a4d15ba3609 · 2024-12-18T11:23:05.000Z
Seems easier to understand than mapping over 0, 1, and 2 and extracting
the column.
diff --git a/03_triangles.rb b/03_triangles.rb
@@ -6,7 +6,5 @@ def tri?(a, b, c)
 
 puts input.count { |x| tri?(*x.sort) }
 puts input.each_slice(3).sum { |rows|
-  [0, 1, 2].count { |col|
-    tri?(*rows.map { |r| r[col] }.sort)
-  }
+  rows.transpose.count { |x| tri?(*x.sort) }
 }

Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,5 @@ def tri?(a, b, c)`
`6`	`6`
`7`	`7`	`puts input.count { \|x\| tri?(*x.sort) }`
`8`	`8`	`puts input.each_slice(3).sum { \|rows\|`
`9`		`- [0, 1, 2].count { \|col\|`
`10`		`- tri?(*rows.map { \|r\| r[col] }.sort)`
`11`		`- }`
	`9`	`+ rows.transpose.count { \|x\| tri?(*x.sort) }`
`12`	`10`	`}`