From 35cf750af8c429be1dc7c921fcc63f517ba1df50 Mon Sep 17 00:00:00 2001
From: Kuaku <kuaku.email@gmail.com>
Date: Thu, 19 Dec 2024 22:19:24 +0100
Subject: [PATCH] [ADD] Added day 19 solution part 2

---
 19/main.go | 86 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 62 insertions(+), 24 deletions(-)

diff --git a/19/main.go b/19/main.go
index 428529e..ab34fc3 100644
--- a/19/main.go
+++ b/19/main.go
@@ -43,41 +43,79 @@ func TransformInput(lines []string) structuredInput {
 	return Puzzle{strings.Split(lines[0], ", "), lines[2:]}
 }
 
+var poss []string
+var cachePart1 map[string]bool = make(map[string]bool)
+
+func hasSolution(input string) bool {
+	if len(input) == 0 {
+		return true
+	}
+
+	value, ok := cachePart1[input]
+
+	if ok {
+		return value
+	}
+
+	var result = false
+
+	for i := 0; i < len(poss); i++ {
+		if len(input) >= len(poss[i]) && input[:len(poss[i])] == poss[i] && hasSolution(input[len(poss[i]):]) {
+			result = true
+			break
+		}
+	}
+
+	cachePart1[input] = result
+	return result
+}
+
 func Part1(input structuredInput) int {
 	var result = 0
-	var poss []string
-	var found bool
-	var work string
+	poss = input.poss
 
-	for i, line := range input.lines {
-		fmt.Println(i)
-		poss = []string{line}
-		found = false
-		for !found && len(poss) > 0 {
-			work = poss[0]
-			poss = poss[1:]
-			for j := 0; j < len(input.poss); j++ {
-				if len(input.poss[j]) <= len(work) {
-					if work[:len(input.poss[j])] == input.poss[j] {
-						poss = append(poss, work[len(input.poss[j]):])
-						if len(work[len(input.poss[j]):]) == 0 {
-							found = true
-							break
-						}
-					}
-				}
-			}
-		}
-		if found {
-			result += 1
+	for _, line := range input.lines {
+		if hasSolution(line) {
+			result++
 		}
 	}
 
 	return result
 }
 
+var cachePart2 map[string]int = make(map[string]int)
+
+func findSolutionCount(input string) int {
+	if len(input) == 0 {
+		return 1
+	}
+
+	value, ok := cachePart2[input]
+
+	if ok {
+		return value
+	}
+
+	var result = 0
+
+	for i := 0; i < len(poss); i++ {
+		if len(input) >= len(poss[i]) && input[:len(poss[i])] == poss[i] {
+			result += findSolutionCount(input[len(poss[i]):])
+		}
+	}
+
+	cachePart2[input] = result
+	return result
+}
+
 func Part2(input structuredInput) int {
 	var result = 0
+	poss = input.poss
+
+	for _, line := range input.lines {
+		result += findSolutionCount(line)
+	}
+
 	return result
 }