day2, example ok

day2/day-two.go

@@ -0,0 +1,100 @@
+package day2
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var Restriction map[string]int = map[string]int{
+	"red": 12,
+	"green": 13,
+	"blue": 14,
+}
+
+type Game struct {
+	Num int
+	Sets [3]map[string]int
+}
+
+// now i need to encode the restriction,
+// code 'compare game to restriction'
+// scan though input lines, keep only numbers of games that pass the restriction, or rather sum them
+
+func Run() int {
+	filename := "./day2/example"
+	file, err := os.Open(filename)
+	if err != nil {
+		panic(fmt.Sprintf("error opening file", filename))
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+
+	result := 0
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		game := ReadLine(line)
+		log.Printf("reading %s got game %+v it is %t", line, game, game.isPossible(Restriction))
+		if game.isPossible(Restriction) {
+			result += game.Num
+		}
+	}
+
+	return result
+}
+
+func (g Game)isPossible(restriction map[string]int) bool {
+	for color, maxAmount := range restriction {
+		for _, set := range g.Sets {
+			seenAmount, found := set[color]
+			if found && seenAmount > maxAmount {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func ReadLine(line string) Game {
+	result := Game{}
+
+	infoIndex := strings.IndexRune(line, ':')
+	gameTitle := line[0:infoIndex]
+	titleNumStr := strings.Split(gameTitle, " ")[1]
+	titleNum, err := strconv.Atoi(titleNumStr)
+	if err != nil {
+		panic(fmt.Sprintf("error getting game number from %s\n", line))
+	}
+	result.Num = titleNum
+
+	setsLints := strings.Split(line[infoIndex+1:], ";")
+	for i, set := range setsLints {
+		result.Sets[i] = readSet(set)
+	}
+	return result
+}
+
+// line like this
+// 8 green, 6 blue, 20 red
+func readSet(setLine string) map[string]int {
+	result := make(map[string]int)
+	itemLines := strings.Split(setLine, ",")
+	for _, line := range itemLines {
+		keyValue := strings.Split(strings.Trim(line, " "), " ")
+		if len(keyValue) != 2 {
+			panic(fmt.Sprintf("part '%s' of '%s' was of wrong lenght! %+v len is %d", line, setLine, keyValue, len(keyValue)))
+		}
+		num, err := strconv.Atoi(keyValue[0])
+		if err != nil {
+			panic(fmt.Sprint(setLine, line, err))
+		}
+		result[keyValue[1]] = num
+	}
+
+	return result
+}

day2/example

@@ -0,0 +1,5 @@
+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green

main.go

@@ -1,13 +1,13 @@
 package main
 
 import (
-	"fmt"
+	"log"
 
-	dayone "sunshine.industries/aoc2023/day1"
+	"sunshine.industries/aoc2023/day2"
 )
 
 func main() {
-     s := "yoyo!"
-     fmt.Printf("hello, %s\n", s)
-     dayone.Run()
+	log.Print("> starting run:")
+	result := day2.Run()
+	log.Printf("day2 result: %d", result)
 }