refactor with filter() and byName()

day-24/internal/one/solve.go

@@ -2,42 +2,28 @@ package one
 
 import (
 	"bytes"
-	"cmp"
-	"slices"
+	"sort"
 	"strconv"
 	"strings"
-
-	log "github.com/sirupsen/logrus"
 )
 
 func Solve(buf []byte) (int, error) {
 	r := bytes.NewReader(buf)
-	initial, wires, expressions, err := parseLines(r)
+	wires, expressions, err := parseLines(r)
 	if err != nil {
 		return 0, err
 	}
 
-	for k, v := range initial {
-		wires[k] = v
-	}
-
 	wires = calculateWire(expressions, wires)
-
-	zWires := []zWire{}
-	for k, v := range wires {
-		if strings.HasPrefix(k, "z") {
-			zWires = append(zWires, zWire{k, v})
-		}
-	}
-	slices.SortFunc(zWires, func(a, b zWire) int {
-		return cmp.Compare(b.name, a.name)
+	zWires := filter(wires, func(name string) bool {
+		return strings.HasPrefix(name, "z")
 	})
+	sort.Sort(byName(zWires))
 
 	var binStr strings.Builder
 	for _, zWire := range zWires {
-		binStr.WriteString(strconv.FormatInt(int64(zWire.value), 2))
+		binStr.WriteString(strconv.Itoa(zWire.value))
 	}
-	log.Debug(binStr.String())
 
 	return mustConvBinToDec(binStr.String()), nil
 }

day-24/internal/one/util.go

@@ -13,7 +13,7 @@ const (
 	target
 )
 
-func parseLines(r io.Reader) (map[string]int, map[string]int, []expression, error) {
+func parseLines(r io.Reader) (map[string]int, []expression, error) {
 	initial := make(map[string]int)
 	wires := make(map[string]int)
 	expressions := []expression{}
@@ -52,10 +52,14 @@ func parseLines(r io.Reader) (map[string]int, map[string]int, []expression, erro
 	}
 
 	if err := scanner.Err(); err != nil {
-		return nil, nil, nil, err
+		return nil, nil, err
 	}
 
-	return initial, wires, expressions, nil
+	for k, v := range initial {
+		wires[k] = v
+	}
+
+	return wires, expressions, nil
 }
 
 func mustConv(s string) int {
@@ -82,3 +86,13 @@ func mustConvBinToDec(s string) int {
 	}
 	return int(n)
 }
+
+func filter(wires map[string]int, fn func(string) bool) []zWire {
+	var filtered []zWire
+	for name, value := range wires {
+		if fn(name) {
+			filtered = append(filtered, zWire{name, value})
+		}
+	}
+	return filtered
+}

day-24/internal/one/zwire.go

@@ -2,6 +2,18 @@ package one
 
 const noValue = -1
 
+type byName []zWire
+
+func (b byName) Len() int {
+	return len(b)
+}
+func (b byName) Less(i, j int) bool {
+	return b[j].name < b[i].name
+}
+func (b byName) Swap(i, j int) {
+	b[i], b[j] = b[j], b[i]
+}
+
 type zWire struct {
 	name  string
 	value int