Start day 2

day01/day01.go

@@ -25,9 +25,7 @@ func atoi(s string) int {
 	return v
 }
 
-func Part01() int {
-	lines := InputLines("./day01/input")
-	var leftCol, rightCol []int
+func getSortedCols(lines []string) (leftCol []int, rightCol []int) {
 	for _, line := range lines {
 		left, right, found := strings.Cut(line, "   ")
 		if found {
@@ -35,10 +33,16 @@ func Part01() int {
 			rightCol = append(rightCol, atoi(right))
 		}
 	}
-
 	slices.Sort(leftCol)
 	slices.Sort(rightCol)
 
+	return leftCol, rightCol
+}
+
+func Part01() int {
+	lines := InputLines("./day01/input")
+	leftCol, rightCol := getSortedCols(lines)
+
 	var diffCols []int
 	for i, val := range leftCol {
 		diffCols = append(diffCols, int(math.Abs(float64((val - rightCol[i])))))
@@ -49,6 +53,22 @@ func Part01() int {
 		sumDiff += diff
 	}
 
-	//fmt.Printf("%v", sumDiff)
 	return sumDiff
 }
+
+func Part02() int {
+	lines := InputLines("./day01/input")
+	leftCol, rightCol := getSortedCols(lines)
+
+	freqsRightCol := make(map[int]int)
+	for _, num := range rightCol {
+		freqsRightCol[num] += 1
+	}
+
+	var similarity int
+	for _, num := range leftCol {
+		similarity += freqsRightCol[num] * num
+	}
+
+	return similarity
+}

day02/day02.go

@@ -0,0 +1,20 @@
+package day02
+
+import (
+	/*
+	"os"
+	"strings"
+	"strconv"
+	"fmt"
+	"slices"
+	"math"
+	*/
+)
+
+func Part01() int {
+	return 420
+}
+
+func Part02() int {
+	return 69
+}

main.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/bdnugget/AoC_2024/day01"
+	"github.com/bdnugget/AoC_2024/day02"
 )
 
 func measureAndPrint[T any](label string, fn func() T) {
@@ -17,4 +18,7 @@ func measureAndPrint[T any](label string, fn func() T) {
 
 func main() {
 	measureAndPrint("Day 01 part 01", day01.Part01)
+	measureAndPrint("Day 01 part 02", day01.Part02)
+	measureAndPrint("Day 02 part 01", day02.Part01)
+	measureAndPrint("Day 02 part 02", day02.Part02)
 }