day5

day5/input0.txt

@@ -0,0 +1,12 @@
+3-5
+10-14
+16-20
+19-19
+12-18
+
+1
+5
+8
+11
+17
+32

day5/main.go

@@ -0,0 +1,125 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func main() {
+	filename := "input0.txt"
+	if len(os.Args) > 1 {
+		filename = os.Args[1]
+	}
+	lines := readLines(filename)
+	kitchen := parseKitchen(lines)
+	fmt.Printf("%d\n", kitchen.countFreshIngredients())
+	fmt.Printf("%d\n", kitchen.countEverythingFresh())
+}
+
+func readLines(filename string) []string {
+	raw, err := os.ReadFile(filename)
+	if err != nil {
+		panic(err)
+	}
+	return strings.Split(string(raw), "\n")
+}
+
+type container struct {
+	start uint64
+	stop  uint64
+}
+
+func (i container) contains(id uint64) bool {
+	return i.start <= id && i.stop >= id
+}
+
+type kitchen struct {
+	coolers     []container
+	ingredients []uint64
+}
+
+func (k kitchen) countFreshIngredients() uint64 {
+	total := uint64(0)
+INGREDIENTS:
+	for _, ingredient := range k.ingredients {
+		for _, cooler := range k.coolers {
+			if cooler.contains(ingredient) {
+				total++
+				continue INGREDIENTS
+			}
+		}
+	}
+	return total
+}
+
+func parseKitchen(lines []string) kitchen {
+	k := kitchen{
+		coolers:     []container{},
+		ingredients: []uint64{},
+	}
+	coolers := true
+	for _, line := range lines {
+		if line == "" {
+			coolers = false
+			continue
+		}
+		if coolers {
+			parts := strings.Split(line, "-")
+			cooler := container{}
+			cooler.start, _ = strconv.ParseUint(parts[0], 10, 64)
+			cooler.stop, _ = strconv.ParseUint(parts[1], 10, 64)
+			k.coolers = append(k.coolers, cooler)
+		} else {
+			id, _ := strconv.ParseUint(line, 10, 64)
+			k.ingredients = append(k.ingredients, id)
+		}
+	}
+	return k
+}
+
+func (k kitchen) countEverythingFresh() uint64 {
+	type pivot struct {
+		id    uint64
+		start bool
+	}
+	pivots := []pivot{}
+	for _, cooler := range k.coolers {
+		pivots = append(pivots,
+			pivot{id: cooler.start, start: true},
+			pivot{id: cooler.stop, start: false},
+		)
+	}
+	sort.Slice(pivots, func(i, j int) bool {
+		pi, pj := pivots[i], pivots[j]
+		if pi.id < pj.id {
+			return true
+		}
+		if pi.id > pj.id {
+			return false
+		}
+		if !pi.start && pj.start {
+			return false
+		}
+		return true
+	})
+	total := uint64(0)
+	insideStarted := uint64(0)
+	within := uint16(0)
+	for _, pivot := range pivots {
+		if pivot.start {
+			if within == 0 {
+				insideStarted = pivot.id
+			}
+			within++
+		} else {
+			within--
+			if within == 0 {
+				total += 1 + pivot.id - insideStarted
+			}
+		}
+	}
+	return total
+}