day 13 part 1

day13/sample1.in

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+#.##..##.
+..#.##.#.
+##......#
+##......#
+..#.##.#.
+..##..##.
+#.#.##.#.
+
+#...##..#
+#....#..#
+..##..###
+#####.##.
+#####.##.
+..##..###
+#....#..#

day13/sol.tcl

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+#!/usr/bin/env tclsh
+source ../prelude.tcl
+
+set input stdin
+set patterns [read $input]
+set patterns [string trim $patterns]
+#puts "$patterns"
+set patterns [string map {"\n\n" "|"} $patterns]
+#puts "$patterns"
+set patterns [split $patterns "|"]
+#puts "$patterns"
+set patterns [lmap p $patterns {split $p "\n"}]
+puts "$patterns"
+#puts "$patterns"
+
+proc reflect pattern {
+    set total 0
+    foreach pat [list $pattern [transpose $pattern]] factor {100 1} {
+        #puts "reflect $pat"
+        for {set i 1} {$i < [llength $pat]} {incr i} {
+            set ok 1
+            for {set j 0} {$i + $j < [llength $pat] && $i-$j-1 >= 0} {incr j} {
+                if {[lindex $pat $i+$j] ne [lindex $pat [expr {$i-$j-1}]]} {
+                    set ok 0
+                    break
+                }
+            }
+            if {$ok} {
+                #puts "$i $factor"
+                incr total [expr {$i * $factor}]
+            }
+        }
+    }
+    return $total
+}
+
+proc column {lst i} {
+    set c {}
+    foreach row $lst {
+        lappend c [string index $row $i]
+    }
+    return [join $c ""]
+}
+
+proc transpose pat {
+    set C [string length [lindex $pat 0]]
+    set out {}
+    for {set i 0} {$i < $C} {incr i} {
+        lappend out [column $pat $i]
+    }
+    return $out
+}
+
+foreach pat $patterns {
+    puts "[reflect $pat] <| $pat"
+}
+
+puts [ladd [lmap pat $patterns {reflect $pat}]]