chore: add day 14

day14/main.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	aoc "go.sour.is/advent-of-code-2023"
+	"golang.org/x/exp/maps"
 )
 
 // var log = aoc.Log
@@ -21,75 +22,57 @@ type result struct {
 func (r result) String() string { return fmt.Sprintf("%#v", r) }
 
 func run(scan *bufio.Scanner) (*result, error) {
-	var maps []Map
+	var maplist []Map
 	var m Map
 
 	for scan.Scan() {
 		text := scan.Text()
 		if len(text) == 0 {
-			maps = append(maps, m)
+			maplist = append(maplist, m)
 			m = Map{}
 		}
 
 		m = append(m, []rune(text))
 	}
-	maps = append(maps, m)
+	maplist = append(maplist, m)
 
 	score1 := 0
-	for _, m := range maps {
+	for _, m := range maplist {
 		m = aoc.Transpose(reverse(m))
 		m.Sort()
 		score1 += m.Score()
 	}
 
 	score2 := 0
-	// type record [5]int
-	// var last, current record
-	// memo := make(map[record]int)
+	type record [5]int
+	var current record
+	memo := make(map[record]int)
 
-	// for _, m := range maps {
-	// 	fmt.Println(m)
+	for _, m := range maplist {
+		// fmt.Println(m)
 
-	// 	m = aoc.Transpose(reverse(m))
+		m = aoc.Transpose(reverse(m))
 
-	// 	for i := 0; i < 1_000_000_000; i++ {
-	// 		m.Sort()
-	// 		current[0] = m.Score()
+		for i := 0; i < 1_000_000_000; i++ {
+			m, current = cycle(m)
 
-	// 		m = aoc.Transpose(reverse(m))
-	// 		m.Sort()
-	// 		current[1] = m.Score()
+			v, ok := memo[current]
+			if ok && v > 1 {
+				counts := aoc.Reduce(
+					func(i int, v int, counts [3]int) [3]int {
+						counts[v]++
+						return counts
+					}, [3]int{}, maps.Values(memo)...)
 
-	// 		m = aoc.Transpose(reverse(m))
-	// 		m.Sort()
-	// 		current[2] = m.Score()
-
-	// 		m = aoc.Transpose(reverse(m))
-	// 		m.Sort()
-	// 		current[3] = m.Score()
-
-	// 		m = aoc.Transpose(reverse(m))
-	// 		current[4] = m.Score()
-
-	// 		if slices.Equal(last[:], current[:]) {
-	// 			break
-	// 		}
-
-	// 		v, ok := memo[current]
-	// 		if (i - 104) % 13 == 12 {
-	// 			fmt.Println(i, current, ok, v)
-	// 		}
-	// 		// if ok && v > 2 {
-	// 		// 	break
-	// 		// }
-
-	// 		memo[current] += 1
-
-	// 		last = current
-	// 	}
-
-	// 	score2 += m.Score()
-	// }
+				// fmt.Println(i, counts)
+				i = 1_000_000_000 - (1_000_000_000-counts[0]-counts[1])%counts[2]
+				clear(memo)
+			}
+			memo[current] += 1
+			// fmt.Println(i, current, v)
+		}
+		score2 += m.Score()
+	}
 
 	return &result{valuePT1: score1, valuePT2: score2}, nil
 }
@@ -149,3 +132,27 @@ func reverse(m Map) Map {
 	}
 	return m
 }
+
+func cycle(m Map) (Map, [5]int) {
+	var current [5]int
+
+	m.Sort()
+	current[0] = m.Score()
+
+	m = aoc.Transpose(reverse(m))
+	m.Sort()
+	current[1] = m.Score()
+
+	m = aoc.Transpose(reverse(m))
+	m.Sort()
+	current[2] = m.Score()
+
+	m = aoc.Transpose(reverse(m))
+	m.Sort()
+	current[3] = m.Score()
+
+	m = aoc.Transpose(reverse(m))
+	current[4] = m.Score()
+
+	return m, current
+}