use deque in fish solution

day06/part1.lua

@@ -1,26 +1,26 @@
 #!/usr/bin/env luajit
 require("utils")
+require("deque")
 
-local fishes = {}
+local fishes = deque()
 for timer = 0, 9 do
-	fishes[timer] = 0
+	fishes:append(0)
 end
 
 for _, timer in pairs(split(io.open(arg[3]):read("*a"), ",")) do
-	fishes[tonumber(timer)] = fishes[tonumber(timer)] + 1
+	fishes:set(tonumber(timer), fishes:get(tonumber(timer)) + 1)
 end
 
 for day = 1, 80 do
-	fishes[9] = (fishes[0] or 0) + (fishes[9] or 0)
-	fishes[7] = (fishes[0] or 0) + (fishes[7] or 0)
-	for timer = 0, 9 do
-		fishes[timer] = fishes[timer + 1]
-	end
+	local breeding = fishes:popleft() or 0
+	fishes:append(0)
+	fishes:set(8, (fishes:get(8) or 0) + breeding)
+	fishes:set(6, (fishes:get(6) or 0) + breeding)
 end
 
 local sum = 0
-for timer, fishday in pairs(fishes) do
-	sum = sum + fishday
+while fishes.size > 0 do
+	sum = sum + (fishes:pop() or 0)
 end
 
 print(sum)

day06/part2.lua

@@ -1,26 +1,26 @@
 #!/usr/bin/env luajit
 require("utils")
+require("deque")
 
-local fishes = {}
+local fishes = deque()
 for timer = 0, 9 do
-	fishes[timer] = 0
+	fishes:append(0)
 end
 
 for _, timer in pairs(split(io.open(arg[3]):read("*a"), ",")) do
-	fishes[tonumber(timer)] = fishes[tonumber(timer)] + 1
+	fishes:set(tonumber(timer), fishes:get(tonumber(timer)) + 1)
 end
 
 for day = 1, 256 do
-	fishes[9] = (fishes[0] or 0) + (fishes[9] or 0)
-	fishes[7] = (fishes[0] or 0) + (fishes[7] or 0)
-	for timer = 0, 9 do
-		fishes[timer] = fishes[timer + 1]
-	end
+	local breeding = fishes:popleft() or 0
+	fishes:append(0)
+	fishes:set(8, (fishes:get(8) or 0) + breeding)
+	fishes:set(6, (fishes:get(6) or 0) + breeding)
 end
 
 local sum = 0
-for timer, fishday in pairs(fishes) do
-	sum = sum + fishday
+while fishes.size > 0 do
+	sum = sum + (fishes:pop() or 0)
 end
 
 print(sum)