101 lines
2.0 KiB
Go
101 lines
2.0 KiB
Go
package day_08
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import (
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"strings"
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)
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type Point struct {
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X, Y int
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}
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// task:https://adventofcode.com/2024/day/8
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func SolveBasic(input string) int {
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antennas, width, height := loadAntennas(input)
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antinodes := map[Point]bool{}
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for _, v := range antennas {
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for i := 0; i < len(v); i++ {
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for j := i + 1; j < len(v); j++ {
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for _, antinode := range findAntinodes(v[i], v[j], width, height) {
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antinodes[antinode] = true
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}
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}
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}
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}
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return len(antinodes)
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}
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// task:https://adventofcode.com/2024/day/8#part2
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func SolveComplex(input string) int {
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antennas, width, height := loadAntennas(input)
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antinodes := map[Point]bool{}
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for _, v := range antennas {
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for i := 0; i < len(v); i++ {
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for j := i + 1; j < len(v); j++ {
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for _, antinode := range findAllAntinodes(v[i], v[j], width, height) {
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antinodes[antinode] = true
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}
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}
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}
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}
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return len(antinodes)
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}
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func findAntinodes(A Point, B Point, width int, height int) []Point {
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dx := B.X - A.X
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dy := B.Y - A.Y
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points := []Point{}
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p := Point{
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X: A.X - dx,
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Y: A.Y - dy,
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}
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if inGrid(p, width, height) {
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points = append(points, p)
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}
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p = Point{
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X: B.X + dx,
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Y: B.Y + dy,
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}
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if inGrid(p, width, height) {
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points = append(points, p)
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}
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return points
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}
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func findAllAntinodes(A Point, B Point, width int, height int) []Point {
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dx := B.X - A.X
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dy := B.Y - A.Y
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points := []Point{}
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for inGrid(A, width, height) {
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points = append(points, Point{A.X, A.Y})
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A.X -= dx
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A.Y -= dy
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}
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for inGrid(B, width, height) {
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points = append(points, Point{B.X, B.Y})
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B.X += dx
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B.Y += dy
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}
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return points
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}
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func inGrid(p Point, width, height int) bool {
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return p.X >= 0 && p.X < width && p.Y >= 0 && p.Y < height
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}
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func loadAntennas(input string) (map[rune][]Point, int, int) {
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results := map[rune][]Point{}
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substrings := strings.Split(input, "\n")
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for y, line := range substrings {
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for x, char := range line {
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if char != '.' {
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results[char] = append(results[char], Point{x, y})
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}
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}
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}
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return results, len(substrings[0]), len(substrings)
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}
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