feat: solve day 3 puzzle 1

README.md

@@ -8,10 +8,10 @@ This project can also be run using the amazing [CraftOS-PC emulator](https://git
 ## Progress
 
 <!-- calendar-start -->
-#### Stars: 4/24
+#### Stars: 5/24
 
 |Mon|Tue|Wed|Thu|Fri|Sat|Sun|
 |:-:|:-:|:-:|:-:|:-:|:-:|:-:|
-|1<br>:star::star:|2<br>:star::star:|3<br>|4<br>|5<br>|6<br>|7<br>|
+|1<br>:star::star:|2<br>:star::star:|3<br>:star:|4<br>|5<br>|6<br>|7<br>|
 |8<br>|9<br>|10<br>|11<br>|12<br>|||
 <!-- calendar-end -->

res/examples/day03.txt

@@ -0,0 +1,4 @@
+987654321111111
+811111111111119
+234234234234278
+818181911112111

res/stats.json

@@ -8,7 +8,7 @@
         "puzzle2": true
     },
     "day03": {
-        "puzzle1": false,
+        "puzzle1": true,
         "puzzle2": false
     },
     "day04": {

src/day03/puzzle1.lua

@@ -0,0 +1,41 @@
+local utils = require("utils")
+local puzzle1 = {}
+
+function puzzle1.bankJoltages(bank)
+    local joltages = {}
+    for i=1, #bank do
+        table.insert(joltages, tonumber(bank:sub(i, i)))
+    end
+    return joltages
+end
+
+function puzzle1.findMaxJoltage(bank)
+    local maxTens = 0
+    local maxJoltage = 0
+    local joltages = puzzle1.bankJoltages(bank)
+
+    for i, tens in ipairs(joltages) do
+        if tens > maxTens then
+            for j=i+1, #joltages do
+                local ones = joltages[j]
+                local joltage = tens * 10 + ones
+                if joltage > maxJoltage then
+                    maxTens = tens
+                    maxJoltage = joltage
+                end
+            end
+        end
+    end
+    return maxJoltage
+end
+
+function puzzle1.solve(input)
+    local banks = utils.splitLines(input)
+    local totalJoltage = 0
+    for _, bank in ipairs(banks) do
+        totalJoltage = totalJoltage + puzzle1.findMaxJoltage(bank)
+    end
+    return totalJoltage
+end
+
+return puzzle1

src/day03/puzzle2.lua

@@ -0,0 +1,7 @@
+local puzzle2 = {}
+
+function puzzle2.solve(input)
+    return 0
+end
+
+return puzzle2