work

2024/go/day22/day22.go

@@ -0,0 +1,91 @@
+package day22
+
+import (
+	"adventofcode2024/utils"
+	rb "adventofcode2024/utils/ringbuffer"
+	"strconv"
+	"strings"
+)
+
+func Part1(input string) int {
+	var secret uint
+	total := 0
+	secrets := strings.Split(input, "\n")
+	for _, secret_str := range secrets {
+		secret = uint(utils.MustAtoi(secret_str))
+		for i := 0; i < 2000; i++ {
+			secret ^= secret * 64
+			secret %= 16777216
+			secret ^= secret / 32
+			secret %= 16777216
+			secret ^= secret * 2048
+			secret %= 16777216
+		}
+		total += int(secret)
+	}
+	return total
+}
+
+func Part2(input string) int {
+	var secret uint
+	var banannas0, banannas1, banannas2, banannas3, banannas4 int
+	seq_map := make(map[string]int)
+	total := 0
+	ringBuffer := rb.NewRingBuffer[uint](5)
+
+	secrets := strings.Split(input, "\n")
+	for _, secret_str := range secrets {
+		found_map := make(map[string]bool)
+		secret = uint(utils.MustAtoi(secret_str))
+		for i := 0; i < 2000; i++ {
+			secret = get_next_secret(secret)
+			ringBuffer.Add(secret)
+			if ringBuffer.Len() < 5 { continue }
+			ring := ringBuffer.Get()
+			banannas0 = get_bannnas(ring[0])
+			banannas1 = get_bannnas(ring[1])
+			banannas2 = get_bannnas(ring[2])
+			banannas3 = get_bannnas(ring[3])
+			banannas4 = get_bannnas(ring[4])
+			map_str := diff_bannanas(banannas1, banannas0) +
+				diff_bannanas(banannas2, banannas1) +
+				diff_bannanas(banannas3, banannas2) +
+				diff_bannanas(banannas4, banannas3)
+			if _, ok := found_map[map_str]; !ok {
+				seq_map[map_str] += banannas4
+				found_map[map_str] = true
+			}
+		}
+	}
+	for _, v := range seq_map {
+		if v > total {
+			total = v
+		}
+	}
+	return total
+}
+
+func get_next_secret(in uint) uint {
+	in ^= in * 64
+	in %= 16777216
+	in ^= in / 32
+	in %= 16777216
+	in ^= in * 2048
+	in %= 16777216
+	return in
+}
+
+func get_bannnas(secret uint) int {
+	return int(secret) % 10
+}
+
+func diff_bannanas(a, b int) string {
+	ret := ""
+	diff := a - b
+	if diff >= 0 {
+		ret = "+" + strconv.Itoa(diff)
+	} else {
+		ret = strconv.Itoa(diff)
+	}
+	return ret
+}

2024/go/day22/day22_test.go

@@ -0,0 +1,20 @@
+package day22
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestPart1(t *testing.T) {
+	r := Part1("1")
+	require.Equal(t, 8685429, r)
+}
+
+func TestPart2(t *testing.T) {
+	r := Part2(`1
+2
+3
+2024`)
+	require.Equal(t, 23, r)
+}