|
|
@@ -0,0 +1,107 @@
|
|
|
+package main
|
|
|
+
|
|
|
+import (
|
|
|
+ "fmt"
|
|
|
+ "io/ioutil"
|
|
|
+ "log"
|
|
|
+ "os"
|
|
|
+ "strconv"
|
|
|
+ "strings"
|
|
|
+)
|
|
|
+
|
|
|
+type octo struct {
|
|
|
+ value int
|
|
|
+ flashed bool
|
|
|
+}
|
|
|
+
|
|
|
+func readInput(file string) [][]octo {
|
|
|
+ content, err := ioutil.ReadFile(file)
|
|
|
+ if err != nil {
|
|
|
+ log.Fatal(err)
|
|
|
+ }
|
|
|
+
|
|
|
+ lines := strings.Split(string(content), "\n")
|
|
|
+ var input [][]octo
|
|
|
+ for _, line := range lines {
|
|
|
+ if line == "" {
|
|
|
+ continue
|
|
|
+ }
|
|
|
+
|
|
|
+ var row []octo
|
|
|
+ for _, char := range line {
|
|
|
+ if number, err := strconv.Atoi(string(char)); err == nil {
|
|
|
+ row = append(row, octo{number, false})
|
|
|
+ } else {
|
|
|
+ log.Fatal(err)
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ input = append(input, row)
|
|
|
+ }
|
|
|
+
|
|
|
+ return input
|
|
|
+}
|
|
|
+
|
|
|
+func doNeighbors(input [][]octo, x, y int) int {
|
|
|
+ var neighbors int
|
|
|
+ for i := -1; i <= 1; i++ {
|
|
|
+ for j := -1; j <= 1; j++ {
|
|
|
+ if i == 0 && j == 0 {
|
|
|
+ continue
|
|
|
+ }
|
|
|
+
|
|
|
+ if x+i < 0 || x+i >= len(input[y]) {
|
|
|
+ continue
|
|
|
+ }
|
|
|
+
|
|
|
+ if y+j < 0 || y+j >= len(input) {
|
|
|
+ continue
|
|
|
+ }
|
|
|
+
|
|
|
+ if !input[y+j][x+i].flashed {
|
|
|
+ input[y+j][x+i].value++
|
|
|
+
|
|
|
+ if input[y+j][x+i].value > 9 {
|
|
|
+ input[y+j][x+i].value = 0
|
|
|
+ input[y+j][x+i].flashed = true
|
|
|
+ neighbors++
|
|
|
+ neighbors += doNeighbors(input, x+i, y+j)
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return neighbors
|
|
|
+}
|
|
|
+
|
|
|
+func part1(input [][]octo) int {
|
|
|
+ var flashed int
|
|
|
+ for i := 0; i < 10; i++ {
|
|
|
+ for y, row := range input {
|
|
|
+ for x, _ := range row {
|
|
|
+ if input[y][x].flashed {
|
|
|
+ input[y][x].flashed = false
|
|
|
+ }
|
|
|
+
|
|
|
+ input[y][x].value++
|
|
|
+ if input[y][x].value > 9 {
|
|
|
+ input[y][x].value = 0
|
|
|
+ input[y][x].flashed = true
|
|
|
+ flashed++
|
|
|
+ flashed += doNeighbors(input, x, y)
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return flashed
|
|
|
+}
|
|
|
+
|
|
|
+func main() {
|
|
|
+ if len(os.Args) < 2 {
|
|
|
+ log.Fatal("Please provide a file name as argument")
|
|
|
+ }
|
|
|
+
|
|
|
+ input := readInput(os.Args[1])
|
|
|
+ fmt.Println(part1(input))
|
|
|
+}
|
