Add solution for Day 1

src/Day01.kt

@@ -1,15 +1,51 @@
 fun main() {
     fun part1(input: List<String>): Int {
-        return input.size
+        var calories = 0
+        var maxCalories = 0
+        input.forEach {
+            if (it.isBlank()) {
+                if (calories > maxCalories) {
+                    maxCalories = calories
+                }
+                calories = 0
+            } else {
+                calories += it.toInt()
+            }
+        }
+        return maxCalories
     }
 
     fun part2(input: List<String>): Int {
-        return input.size
+        var calories = 0
+        var maxCalories = 0
+        var secondMaxCalories = 0
+        var thirdMaxCalories = 0
+        input.forEachIndexed { index, food ->
+            if (food.isBlank() || index == input.lastIndex) {
+                if (index == input.lastIndex) {
+                    calories = food.toInt()
+                }
+                if (calories >= maxCalories) {
+                    thirdMaxCalories = secondMaxCalories
+                    secondMaxCalories = maxCalories
+                    maxCalories = calories
+                } else if (calories >= secondMaxCalories) {
+                    thirdMaxCalories = secondMaxCalories
+                    secondMaxCalories = calories
+                } else if (calories > thirdMaxCalories) {
+                    thirdMaxCalories = calories
+                }
+                calories = 0
+            } else {
+                calories += food.toInt()
+            }
+        }
+        return maxCalories + secondMaxCalories + thirdMaxCalories
     }
 
-    // test if implementation meets criteria from the description, like:
     val testInput = readInput("Day01_test")
-    check(part1(testInput) == 1)
+    check(part1(testInput) == 24000)
+    check(part2(testInput) == 45000)
 
     val input = readInput("Day01")
     println(part1(input))