day10

day10p1/solution.go

@@ -0,0 +1,52 @@
+package day10p1
+
+import (
+	"io"
+
+	"aoc/utils"
+)
+
+type position struct {
+	x, y int
+}
+
+func Solve(r io.Reader) any {
+	lines := utils.ReadLines(r)
+
+	board := make([][]int, len(lines))
+	for i, line := range lines {
+		board[i] = make([]int, len(line))
+		for j, c := range line {
+			board[i][j] = int(c) - int('0')
+		}
+	}
+
+	scores := 0
+
+	for i, row := range board {
+		for j, _ := range row {
+			if row[j] != 0 {
+				continue
+			}
+			visited := make(map[position]bool)
+			queue := []position{{i, j}}
+			for len(queue) > 0 {
+				pos := queue[0]
+				queue = queue[1:]
+				if board[pos.x][pos.y] == 9 {
+					if !visited[pos] {
+						scores++
+					}
+					visited[pos] = true
+				}
+				for _, dir := range []position{{0, 1}, {0, -1}, {1, 0}, {-1, 0}} {
+					if pos.x+dir.x >= 0 && pos.x+dir.x < len(board) && pos.y+dir.y >= 0 && pos.y+dir.y < len(board[0]) && (board[pos.x+dir.x][pos.y+dir.y]-board[pos.x][pos.y]) == 1 {
+						queue = append(queue, position{pos.x + dir.x, pos.y + dir.y})
+					}
+				}
+			}
+		}
+	}
+
+	return scores
+}

day10p1/solution_test.go

@@ -0,0 +1,40 @@
+package day10p1
+
+import (
+	"strings"
+	"testing"
+
+	"aoc/utils"
+)
+
+var testInput = `89010123
+78121874
+87430965
+96549874
+45678903
+32019012
+01329801
+10456732`
+
+func TestSolve(t *testing.T) {
+	tests := []struct {
+		input  string
+		answer int
+	}{
+		{testInput, 36},
+	}
+
+	if testing.Verbose() {
+		utils.Verbose = true
+	}
+
+	for _, test := range tests {
+		r := strings.NewReader(test.input)
+
+		result := Solve(r).(int)
+
+		if result != test.answer {
+			t.Errorf("Expected %d, got %d", test.answer, result)
+		}
+	}
+}

day10p2/solution.go

@@ -0,0 +1,48 @@
+package day10p2
+
+import (
+	"io"
+
+	"aoc/utils"
+)
+
+type position struct {
+	x, y int
+}
+
+func Solve(r io.Reader) any {
+	lines := utils.ReadLines(r)
+
+	board := make([][]int, len(lines))
+	for i, line := range lines {
+		board[i] = make([]int, len(line))
+		for j, c := range line {
+			board[i][j] = int(c) - int('0')
+		}
+	}
+
+	scores := 0
+
+	for i, row := range board {
+		for j, _ := range row {
+			if row[j] != 0 {
+				continue
+			}
+			queue := []position{{i, j}}
+			for len(queue) > 0 {
+				pos := queue[0]
+				queue = queue[1:]
+				if board[pos.x][pos.y] == 9 {
+					scores++
+				}
+				for _, dir := range []position{{0, 1}, {0, -1}, {1, 0}, {-1, 0}} {
+					if pos.x+dir.x >= 0 && pos.x+dir.x < len(board) && pos.y+dir.y >= 0 && pos.y+dir.y < len(board[0]) && (board[pos.x+dir.x][pos.y+dir.y]-board[pos.x][pos.y]) == 1 {
+						queue = append(queue, position{pos.x + dir.x, pos.y + dir.y})
+					}
+				}
+			}
+		}
+	}
+
+	return scores
+}

day10p2/solution_test.go

@@ -0,0 +1,40 @@
+package day10p2
+
+import (
+	"strings"
+	"testing"
+
+	"aoc/utils"
+)
+
+var testInput = `89010123
+78121874
+87430965
+96549874
+45678903
+32019012
+01329801
+10456732`
+
+func TestSolve(t *testing.T) {
+	tests := []struct {
+		input  string
+		answer int
+	}{
+		{testInput, 81},
+	}
+
+	if testing.Verbose() {
+		utils.Verbose = true
+	}
+
+	for _, test := range tests {
+		r := strings.NewReader(test.input)
+
+		result := Solve(r).(int)
+
+		if result != test.answer {
+			t.Errorf("Expected %d, got %d", test.answer, result)
+		}
+	}
+}