feat: add day 5 2024

aoc2024/day05/main.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"bufio"
+	_ "embed"
+	"fmt"
+	"sort"
+	"strings"
+
+	aoc "go.sour.is/advent-of-code"
+)
+
+// var log = aoc.Log
+
+func main() { aoc.MustResult(aoc.Runner(run)) }
+
+type result struct {
+	valuePT1 int
+	valuePT2 int
+}
+
+func (r result) String() string { return fmt.Sprintf("%#v", r) }
+
+func run(scan *bufio.Scanner) (*result, error) {
+
+	ordering := make(map[int]aoc.Set[int])
+	var updates [][]int
+
+	for scan.Scan() {
+		txt := scan.Text()
+
+		if txt == "" {
+			break
+		}
+
+		var key, val int
+		_, err := fmt.Sscanf(txt, "%d|%d", &val, &key)
+		if err != nil {
+			return nil, err
+		}
+		if _, ok := ordering[key]; !ok {
+			ordering[key] = aoc.NewSet[int]()
+		}
+		s := ordering[key]
+		s.Add(val)
+	}
+
+	var sum int
+	var sum2 int
+
+outer:
+	for scan.Scan() {
+		txt := scan.Text()
+
+		arr := aoc.SliceMap(aoc.Atoi, strings.Split(txt, ",")...)
+
+		for i, v := range arr {
+			m, ok := ordering[v]
+			if (i > 0 && !ok) || !m.ContainsAll(arr[:i]...) {
+				sort.SliceStable(arr, func(i, j int) bool {
+					if a, ok := ordering[arr[i]]; ok && a.Has(arr[j]) {
+						return true
+					}
+
+					if b, ok := ordering[arr[j]]; ok && b.Has(arr[i]) {
+						return false
+					}
+
+					return false
+				})
+
+				sum2 += arr[len(arr)/2]
+
+				continue outer
+			}
+		}
+
+		sum += arr[len(arr)/2]
+		updates = append(updates, arr)
+	}
+
+	return &result{sum, sum2}, nil
+}