feat: solve day 6 puzzle 2

src/day06/puzzle2.lua

@@ -1,7 +1,58 @@
+local strings = require "cc.strings"
 local puzzle2 = {}
 
+function puzzle2.parseNumbers(lines)
+    local numbers = {}
+    local n = #lines
+
+    for i, line in ipairs(lines) do
+        if i ~= n then
+            for j=1, #line do
+                local c = line:sub(j, j)
+                if #numbers < j then
+                    table.insert(numbers, {})
+                end
+                if c ~= " " then
+                    table.insert(numbers[j], c)
+                end
+            end
+        end
+    end
+
+    local problems = {{}}
+    for _, num in ipairs(numbers) do
+        if #num == 0 then
+            table.insert(problems, {})
+        else
+            local value = tonumber(table.concat(num, ""))
+            table.insert(problems[#problems], value)
+        end
+    end
+    return problems
+end
+
 function puzzle2.solve(input)
-    return 0
+    local lines = strings.split(input, "\n")
+    local values = puzzle2.parseNumbers(lines)
+    local ops = strings.split(lines[#lines], "%s+")
+
+    local total = 0
+    for p, numbers in ipairs(values) do
+        local op = ops[p]
+        local value = 0
+        if op == "*" then
+            value = 1
+        end
+        for _, num in ipairs(numbers) do
+            if op == "+" then
+                value = value + num
+            else
+                value = value * num
+            end
+        end
+        total = total + value
+    end
+    return total
 end
 
 return puzzle2