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alokmenghrajanialokmenghrajani
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days 16, 17, and 18
1 parent fdefad5 commit 68ef972

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12 files changed

+1173
-3
lines changed

12 files changed

+1173
-3
lines changed

‎day16/day16.go

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package day16
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import (
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"regexp"
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"strings"
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"github.com/alokmenghrajani/adventofcode2020/utils"
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)
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type rule struct {
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name string
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min1, max1, min2, max2 int
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offsets map[int]bool
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final int
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}
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func Part1(input string) int {
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var rules []rule
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parts := strings.Split(input, "\n\n")
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for _, line := range strings.Split(parts[0], "\n") {
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re := regexp.MustCompile(`^(.*?): (\d+)-(\d+) or (\d+)-(\d+)`)
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match := re.FindStringSubmatch(line)
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r := rule{
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name: match[1],
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min1: utils.MustAtoi(match[2]),
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max1: utils.MustAtoi(match[3]),
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min2: utils.MustAtoi(match[4]),
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max2: utils.MustAtoi(match[5]),
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offsets: map[int]bool{},
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}
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rules = append(rules, r)
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}
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res := 0
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t := strings.Split(parts[2], "\n")
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for _, line := range t[1:] {
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for _, n := range strings.Split(line, ",") {
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n2 := utils.MustAtoi(n)
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ok := false
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for _, r := range rules {
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if (n2 >= r.min1 && n2 <= r.max1) || (n2 >= r.min2 && n2 <= r.max2) {
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ok = true
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break
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}
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}
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if !ok {
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res += n2
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}
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}
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}
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return res
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}
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func Part2(input string) int {
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var rules []rule
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parts := strings.Split(input, "\n\n")
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for _, line := range strings.Split(parts[0], "\n") {
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re := regexp.MustCompile(`^(.*?): (\d+)-(\d+) or (\d+)-(\d+)`)
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match := re.FindStringSubmatch(line)
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r := rule{
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name: match[1],
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min1: utils.MustAtoi(match[2]),
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max1: utils.MustAtoi(match[3]),
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min2: utils.MustAtoi(match[4]),
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max2: utils.MustAtoi(match[5]),
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offsets: map[int]bool{},
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}
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rules = append(rules, r)
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}
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t := strings.Split(parts[2], "\n")
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for _, line := range t[1:] {
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for offset, n := range strings.Split(line, ",") {
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n2 := utils.MustAtoi(n)
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ok := false
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for _, r := range rules {
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if (n2 >= r.min1 && n2 <= r.max1) || (n2 >= r.min2 && n2 <= r.max2) {
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ok = true
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break
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}
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}
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if ok {
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for rnumber, r := range rules {
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if (n2 >= r.min1 && n2 <= r.max1) || (n2 >= r.min2 && n2 <= r.max2) {
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_, tok := rules[rnumber].offsets[offset]
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if !tok {
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rules[rnumber].offsets[offset] = true
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}
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} else {
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rules[rnumber].offsets[offset] = false
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}
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}
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}
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}
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}
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// clean
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for i, _ := range rules {
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for k, v := range rules[i].offsets {
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if !v {
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delete(rules[i].offsets, k)
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}
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}
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}
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// find positions
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done := false
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for !done {
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done = true
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for i, _ := range rules {
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if len(rules[i].offsets) == 1 {
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var k int
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for k, _ = range rules[i].offsets {
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break
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}
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rules[i].final = k
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done = false
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for j, _ := range rules {
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delete(rules[j].offsets, k)
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}
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}
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}
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}
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tickets := strings.Split(parts[1], "\n")
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ticket := strings.Split(tickets[1], ",")
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res := 1
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for _, r := range rules {
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if strings.HasPrefix(r.name, "departure") {
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res = res * utils.MustAtoi(ticket[r.final])
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}
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}
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return res
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}

‎day16/day16_test.go

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package day16
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import (
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"testing"
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"github.com/stretchr/testify/require"
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)
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func TestPart1(t *testing.T) {
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r := Part1(`class: 1-3 or 5-7
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row: 6-11 or 33-44
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seat: 13-40 or 45-50
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your ticket:
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7,1,14
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nearby tickets:
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7,3,47
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40,4,50
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55,2,20
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38,6,12`)
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require.Equal(t, 71, r)
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}

‎day16/input.txt

Lines changed: 264 additions & 0 deletions
Large diffs are not rendered by default.

‎day17/day17.go

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package day17
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import (
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"fmt"
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"strings"
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"github.com/alokmenghrajani/adventofcode2020/utils"
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)
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10+
var minX, maxX, minY, maxY, minZ, maxZ int
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var minZZ, maxZZ int
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func Part1(input string) int {
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g := map[string]bool{}
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for y, line := range strings.Split(input, "\n") {
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for x, c := range line {
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if c == '#' {
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g[makeKey(x, y, 0)] = true
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minX = utils.IntMin(minX, x)
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maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
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}
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}
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}
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for i := 0; i < 6; i++ {
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g = compute(g)
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}
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return len(g)
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}
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func makeKey(x, y, z int) string {
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return fmt.Sprintf("%d:%d:%d", x, y, z)
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}
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func compute(g map[string]bool) map[string]bool {
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rmap := map[string]bool{}
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cMinX := minX
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cMaxX := maxX
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cMinY := minY
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cMaxY := maxY
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cMinZ := minZ
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cMaxZ := maxZ
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for x := cMinX - 1; x <= cMaxX+1; x++ {
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for y := cMinY - 1; y <= cMaxY+1; y++ {
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for z := cMinZ - 1; z <= cMaxZ+1; z++ {
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// count neighbors
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r := 0
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for i := -1; i <= 1; i++ {
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for j := -1; j <= 1; j++ {
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for k := -1; k <= 1; k++ {
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if i == 0 && j == 0 && k == 0 {
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continue
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}
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if g[makeKey(x+i, y+j, z+k)] {
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r++
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}
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}
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}
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}
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if g[makeKey(x, y, z)] {
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if r == 2 || r == 3 {
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rmap[makeKey(x, y, z)] = true
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minX = utils.IntMin(minX, x)
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maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
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minZ = utils.IntMin(minZ, z)
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maxZ = utils.IntMax(maxZ, z)
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}
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} else {
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if r == 3 {
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rmap[makeKey(x, y, z)] = true
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minX = utils.IntMin(minX, x)
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maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
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minZ = utils.IntMin(minZ, z)
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maxZ = utils.IntMax(maxZ, z)
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}
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}
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}
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}
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}
90+
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return rmap
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}
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func Part2(input string) int {
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g := map[string]bool{}
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for y, line := range strings.Split(input, "\n") {
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for x, c := range line {
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if c == '#' {
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g[makeKey2(x, y, 0, 0)] = true
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minX = utils.IntMin(minX, x)
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maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
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}
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}
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}
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for i := 0; i < 6; i++ {
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g = compute2(g)
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}
111+
112+
return len(g)
113+
}
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func compute2(g map[string]bool) map[string]bool {
116+
rmap := map[string]bool{}
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118+
cMinX := minX
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cMaxX := maxX
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cMinY := minY
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cMaxY := maxY
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cMinZ := minZ
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cMaxZ := maxZ
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cMinZZ := minZZ
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cMaxZZ := maxZZ
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for x := cMinX - 1; x <= cMaxX+1; x++ {
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for y := cMinY - 1; y <= cMaxY+1; y++ {
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for z := cMinZ - 1; z <= cMaxZ+1; z++ {
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for zz := cMinZZ - 1; zz <= cMaxZZ+1; zz++ {
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// count neighbors
132+
r := 0
133+
for i := -1; i <= 1; i++ {
134+
for j := -1; j <= 1; j++ {
135+
for k := -1; k <= 1; k++ {
136+
for kk := -1; kk <= 1; kk++ {
137+
if i == 0 && j == 0 && k == 0 && kk == 0 {
138+
continue
139+
}
140+
if g[makeKey2(x+i, y+j, z+k, zz+kk)] {
141+
r++
142+
}
143+
}
144+
}
145+
}
146+
}
147+
148+
if g[makeKey2(x, y, z, zz)] {
149+
if r == 2 || r == 3 {
150+
rmap[makeKey2(x, y, z, zz)] = true
151+
minX = utils.IntMin(minX, x)
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maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
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minZ = utils.IntMin(minZ, z)
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maxZ = utils.IntMax(maxZ, z)
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minZZ = utils.IntMin(minZZ, zz)
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maxZZ = utils.IntMax(maxZZ, zz)
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}
160+
} else {
161+
if r == 3 {
162+
rmap[makeKey2(x, y, z, zz)] = true
163+
minX = utils.IntMin(minX, x)
164+
maxX = utils.IntMax(maxX, x)
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minY = utils.IntMin(minY, y)
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maxY = utils.IntMax(maxY, y)
167+
minZ = utils.IntMin(minZ, z)
168+
maxZ = utils.IntMax(maxZ, z)
169+
minZZ = utils.IntMin(minZZ, zz)
170+
maxZZ = utils.IntMax(maxZZ, zz)
171+
}
172+
}
173+
}
174+
}
175+
}
176+
}
177+
178+
return rmap
179+
}
180+
181+
func makeKey2(x, y, z, zz int) string {
182+
return fmt.Sprintf("%d:%d:%d:%d", x, y, z, zz)
183+
}

‎day17/day17_test.go

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package day17
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import (
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"testing"
5+
6+
"github.com/stretchr/testify/require"
7+
)
8+
9+
func TestPart1(t *testing.T) {
10+
r := Part1(`.#.
11+
..#
12+
###`)
13+
require.Equal(t, 112, r)
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}
15+
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func TestPart2(t *testing.T) {
17+
r := Part2(`.#.
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..#
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###`)
20+
require.Equal(t, 848, r)
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}

‎day17/input.txt

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###..#..
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.#######
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#####...
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#..##.#.
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###..##.
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##...#..
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..#...#.
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.#....##

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