Switched out old logic for day 3 with queue

2024/day3/main.go

@@ -9,6 +9,28 @@ import (
 	"strconv"
 )
 
+type Queue[T any] struct {
+	items []T
+}
+
+func (q *Queue[T]) Enqueue(item T) {
+	q.items = append(q.items, item)
+}
+
+func (q *Queue[T]) Dequeue() T {
+	item := q.items[0]
+	q.items = q.items[1:]
+	return item
+}
+
+func (q *Queue[T]) IsEmpty() bool {
+	return len(q.items) == 0
+}
+
+func (q *Queue[T]) Peek() T {
+	return q.items[0]
+}
+
 func Part1(text string) int {
 	// Regex to match mul(x, y)
 	mulRe := regexp.MustCompile(`(?i)mul\((\d+),(\d+)\)`)
@@ -39,42 +61,32 @@ func Part2(text string) int {
 
 	// Regex to match do quoted strings
 	doRe := regexp.MustCompile("(?i)do\\(\\)")
-	doReMatches := doRe.FindAllStringIndex(text, -1)
+	doQueue := Queue[int]{}
+	for _, match := range doRe.FindAllStringIndex(text, -1) {
+		doQueue.Enqueue(match[0])
+	}
 
 	// Regex to match do quoted strings
 	dontRe := regexp.MustCompile("(?i)don't\\(\\)")
-	dontReMatches := dontRe.FindAllStringIndex(text, -1)
+	dontQueue := Queue[int]{}
+	for _, match := range dontRe.FindAllStringIndex(text, -1) {
+		dontQueue.Enqueue(match[0])
+	}
 
-	lastDoIndex := 0
-	lastDontIndex := 0
 	result := 0
 	for _, match := range mulReMatches {
 		// Find the last instance of do before the current match
-		lastDo := -1
-		for i := lastDoIndex; i < len(doReMatches); i++ {
-			m := doReMatches[i]
-			if match[0] < m[0] {
-				break
-			}
-
-			lastDo = m[0]
-			lastDoIndex = i
+		for !doQueue.IsEmpty() && doQueue.Peek() < match[0] {
+			_ = doQueue.Dequeue()
 		}
 
 		// Find the last instance of don't before the current match
-		lastDont := -1
-		for i := lastDontIndex; i < len(dontReMatches); i++ {
-			m := dontReMatches[i]
-			if match[0] < m[0] {
-				break
-			}
-
-			lastDont = m[0]
-			lastDontIndex = i
+		for !dontQueue.IsEmpty() && dontQueue.Peek() < match[0] {
+			_ = dontQueue.Dequeue()
 		}
 
 		// If the previous don't is after the previous do, skip this match
-		if lastDont > lastDo {
+		if !dontQueue.IsEmpty() && !doQueue.IsEmpty() && dontQueue.Peek() < doQueue.Peek() {
 			continue
 		}