day 2

02/main.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func mustAtoi(line string) int {
+	i, _ := strconv.Atoi(line)
+	return i
+}
+
+func main() {
+	start := time.Now()
+	partOne()
+	duration := time.Since(start)
+	partTwo()
+	duration2 := time.Since(start)
+	fmt.Printf("p1: %s, p2: %s\n", duration, duration2-duration)
+}
+
+func makeScanner(test bool) *bufio.Scanner {
+	var f *os.File
+	if test {
+		f, _ = os.Open("inputs/testinput")
+	} else {
+		f, _ = os.Open("inputs/input")
+	}
+	reader := bufio.NewReader(f)
+	return bufio.NewScanner(reader)
+}
+
+type game struct {
+	red   int
+	green int
+	blue  int
+}
+
+func partOne() {
+	scanner := makeScanner(false)
+
+	sum := 0
+	round := 0
+	max := game{
+		red:   12,
+		green: 13,
+		blue:  14,
+	}
+	for scanner.Scan() {
+		line := scanner.Text()
+		ok := true
+		round++
+		_, draws, _ := strings.Cut(line, ": ")
+		for _, draws := range strings.Split(draws, "; ") {
+			iter := strings.Split(draws, " ")
+			g := game{}
+			for i := 0; i < len(iter); i++ {
+				seen := mustAtoi(iter[i])
+				i++
+				switch iter[i][0] {
+				case 'r':
+					g.red = seen
+				case 'g':
+					g.green = seen
+				case 'b':
+					g.blue = seen
+				}
+			}
+			if g.red > max.red || g.blue > max.blue || g.green > max.green {
+				ok = false
+			}
+		}
+		if ok {
+			sum += round
+		}
+	}
+	fmt.Println(sum)
+}
+
+func partTwo() {
+	scanner := makeScanner(false)
+
+	sum := 0
+	for scanner.Scan() {
+		line := scanner.Text()
+		_, draws, _ := strings.Cut(line, ": ")
+		max := game{}
+		for _, draws := range strings.Split(draws, "; ") {
+			iter := strings.Split(draws, " ")
+			g := game{}
+			for i := 0; i < len(iter); i++ {
+				seen := mustAtoi(iter[i])
+				i++
+				switch iter[i][0] {
+				case 'r':
+					g.red = seen
+				case 'g':
+					g.green = seen
+				case 'b':
+					g.blue = seen
+				}
+			}
+			if g.red > max.red {
+				max.red = g.red
+			}
+			if g.blue > max.blue {
+				max.blue = g.blue
+			}
+			if g.green > max.green {
+				max.green = g.green
+			}
+		}
+		sum += max.blue * max.green * max.red
+	}
+	fmt.Println(sum)
+}