AdventOfCode2021/day15/15a/main.go
Luke Else d7e0ba575c day 15a complete
used help to get solution (see graph library used)
2021-12-16 20:18:54 +00:00

109 lines
2.1 KiB
Go

package main
import (
"bufio"
"fmt"
"os"
"strconv"
"github.com/yourbasic/graph"
)
func main() {
content := returnContent("../input")
//content := returnContent("../testInput")
height := len(*content)
width := len((*content)[0])
g := graph.New(height * width)
for y, line := range *content {
for x, _ := range line {
c := Coordinate{
X: x,
Y: y,
}
myIdx := c.Y*width + c.X
neighbours := c.Neighbours(width, height, false)
for _, neighbour := range neighbours {
neighbourCost := int64((*content)[neighbour.Y][neighbour.X])
neighbourIdx := neighbour.Y*width + neighbour.X
g.AddCost(myIdx, neighbourIdx, neighbourCost)
}
}
}
path, cost := graph.ShortestPath(g, 0, width*height-1)
fmt.Println(path, cost)
}
type Coordinate struct {
X int
Y int
}
func (c *Coordinate) Neighbours(gridWidth int, gridHeight int, diagonal bool) (out []Coordinate) {
spaceLeft := c.X > 0
spaceRight := c.X < gridWidth-1
spaceUp := c.Y > 0
spaceDown := c.Y < gridHeight-1
if spaceLeft {
out = append(out, Coordinate{c.X - 1, c.Y})
}
if spaceRight {
out = append(out, Coordinate{c.X + 1, c.Y})
}
if spaceUp {
out = append(out, Coordinate{c.X, c.Y - 1})
}
if spaceDown {
out = append(out, Coordinate{c.X, c.Y + 1})
}
if diagonal {
if spaceUp && spaceLeft {
out = append(out, Coordinate{c.X - 1, c.Y - 1})
}
if spaceUp && spaceRight {
out = append(out, Coordinate{c.X + 1, c.Y - 1})
}
if spaceDown && spaceLeft {
out = append(out, Coordinate{c.X - 1, c.Y + 1})
}
if spaceDown && spaceRight {
out = append(out, Coordinate{c.X + 1, c.Y + 1})
}
}
return
}
func returnContent(path string) *[][]int {
//read file and return it as an array of integers
file, err := os.Open(path)
var content [][]int
if err != nil {
fmt.Println("Unlucky, the file didn't open")
return &content
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
nums := []int{}
for _, num := range scanner.Text() {
val, _ := strconv.Atoi(string(num))
nums = append(nums, val)
}
content = append(content, nums)
}
return &content
}