day14, example

day14/dayFourteen.go

@@ -0,0 +1,146 @@
+package day14
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func Run() int {
+	fmt.Println("hello day 14")
+
+	field := ReadPlatform("day14/example")
+	fmt.Println(field.String())
+
+	// fmt.Printf("> lines for field %+v\n", field.UpIndices())
+	field.MoveUp(field.Height())
+	fmt.Println(field.String())
+
+	// north rock load
+	return field.NorthLoad()
+}
+
+const Rock rune = 'O'
+const Wall rune = '#'
+const Space rune = '.'
+
+type Platform struct {
+	Rocks [][]rune
+}
+
+func (p *Platform)Height() int {
+	return len(p.Rocks)
+}
+func (p *Platform)Width() int {
+	return len(p.Rocks[0])
+}
+
+func ReadPlatform(filename string) Platform {
+	bytes, err := os.ReadFile(filename)
+	if err != nil {
+		panic(fmt.Sprint("cannot read file: ", filename))
+	}
+	text := string(bytes)
+	text = strings.TrimSpace(text)
+	lines := strings.Split(text, "\n")
+
+	rocks := make([][]rune, len(lines))
+	for i, line := range lines {
+		rocks[i] = []rune(line)
+	}
+
+	return Platform{
+		Rocks: rocks,
+	}
+}
+
+func (p *Platform) String() string {
+	text := "\n"
+	for _, row := range p.Rocks {
+		text += string(row)
+		text += "\n"
+	}
+
+	return text
+}
+
+type Coord struct { Row, Col int }
+
+func (p *Platform) UpIndices() [][]Coord {
+	lines := make([][]Coord,0)
+	for col := 0; col < p.Width(); col++ {
+		line := make([]Coord, 0)
+		for row := 0; row < p.Height(); row++ {
+			line = append(line, Coord{Row: row, Col: col})
+		}
+		lines = append(lines, line)
+	}
+	return lines
+}
+
+func (p *Platform) DownIndices() [][]Coord {
+	lines := make([][]Coord,0)
+	for col := 0; col < p.Width(); col++ {
+		line := make([]Coord, 0)
+		for row := p.Height() - 1; row >= 0; row-- {
+			line = append(line, Coord{Row: row, Col: col})
+		}
+		lines = append(lines, line)
+	}
+	return lines
+}
+
+func (p *Platform)SymbAt(coord Coord) rune {
+	return p.Rocks[coord.Row][coord.Col]
+}
+func (p *Platform)SetSymbAt(coord Coord, symb rune) {
+	p.Rocks[coord.Row][coord.Col] = symb
+}
+
+func (p *Platform) MoveUp(n int) {
+	lines := p.UpIndices()
+
+	for _, line := range lines {
+		moveSize := 0
+		for i, coord := range line {
+			symb := p.SymbAt(coord)
+			switch symb {
+			case Space:
+				moveSize += 1
+				if moveSize > n {
+					moveSize = n
+				}
+			case Wall:
+				moveSize = 0
+			case Rock:
+				if moveSize == 0 {
+					continue
+				}
+				// get coord for moveSize back. and set that to 'o'
+				// and set current to '.'
+				// panic if that place is not '.' i guess
+				moveTo := line[i - moveSize]
+				symbAtTarget := p.SymbAt(moveTo)
+				if symbAtTarget != Space {
+					panic(fmt.Sprintf("attempting to move %+v to %+v, target symbol is %s, not '.'",
+						coord, moveTo, string(symbAtTarget)))
+				}
+				p.SetSymbAt(moveTo, Rock)
+				p.SetSymbAt(coord, Space)
+			}
+		}
+	}
+}
+
+func (p *Platform)NorthLoad() int {
+	total := 0
+	height := p.Height()
+	for i, row := range p.Rocks {
+		for _, symb := range row {
+			if symb == Rock {
+				total += (height - i)
+			}
+		}
+	}
+	return total
+}

day14/example

@@ -0,0 +1,10 @@
+O....#....
+O.OO#....#
+.....##...
+OO.#O....O
+.O.....O#.
+O.#..O.#.#
+..O..#O..O
+.......O..
+#....###..
+#OO..#....

main.go

@@ -3,12 +3,12 @@ package main
 import (
 	"log"
 
-	"sunshine.industries/aoc2023/day13"
+	"sunshine.industries/aoc2023/day14"
 )
 
 func main() {
 	log.Print("> starting run:")
 
-	result := day13.Run()
-	log.Printf("day13 result: %d\n****\n", result)
+	result := day14.Run()
+	log.Printf("day14 result: %d\n****\n", result)
 }