Day 10

10.jl

@@ -0,0 +1,34 @@
+const grid::Vector{Vector{UInt8}} = [ [ UInt8(x) - UInt8('0') for x in collect(line) ] for line in readlines("input/10") ]
+const size = length(grid)
+
+isOnMap(x, y) = 1 <= x <= size && 1 <= y <= size
+
+function checkTrail(x, y, reached)
+	local c = grid[y][x]
+	if c == 9
+		push!(reached, (x,y))
+		return 1
+	end
+	local score = 0
+	for (u,v) in ((x+1, y), (x-1, y),(x, y+1), (x, y-1))
+		if isOnMap(u, v) && grid[v][u] == c+1
+			score += checkTrail(u, v, reached)
+		end
+	end
+	return score
+end
+
+partOne, partTwo = 0, 0
+
+for y in 1:size
+	for x in 1:size
+		if grid[y][x] == 0
+			local reached::Set{Tuple{Int,Int}} = Set()
+			global partTwo += checkTrail(x, y, reached)
+			global partOne += length(reached)
+		end
+	end
+end
+
+@show partOne, partTwo
+