Add Day9.1

src/main/kotlin/Day09.kt

@@ -0,0 +1,73 @@
+import utils.AoCDay
+import utils.splitAndMapToInt
+
+class Day09 : AoCDay() {
+    val lengths = input.first().splitAndMapToInt("")
+    val writes = mutableMapOf<Int, Int>()
+    val spaces = mutableMapOf<Int, Int>()
+
+    init {
+        var id = 0
+        lengths.forEachIndexed { index, length ->
+            if (index % 2 == 0) {
+                writes += id to length
+                id++
+            } else {
+                spaces += (id) to length
+            }
+        }
+    }
+
+    // 2333133121414131402
+    // 2 3 1 3 2 4 4 3 4 2
+
+    override fun part1(): Any {
+        var writeState = true
+        var result = 0L
+
+        var spaces = this.spaces.toMutableMap()
+        var writes = this.writes.toMutableMap()
+
+        var totalIndex = 0
+
+        while (writes.isNotEmpty()) {
+            if (writeState) {
+                val (id, amount) = writes.entries.first()
+                writes.remove(id, amount)
+                repeat(amount) {
+                    result += id * totalIndex.toLong()
+                    totalIndex++
+                }
+                writeState = false
+            } else {
+                if (spaces.isEmpty()) {
+                    writeState = true
+                    continue
+                }
+                val (spaceId, amountOfSpaces) = spaces.entries.first()
+                spaces.remove(spaceId, amountOfSpaces)
+
+                repeat(amountOfSpaces) {
+                    val (id, amountOfWrites) = writes.entries.last()
+                    writes.remove(id, amountOfWrites)
+                    if (amountOfWrites != 1) {
+                        writes += id to amountOfWrites - 1
+                    }
+                    result += id * totalIndex
+                    totalIndex++
+                }
+                writeState = true
+            }
+        }
+
+        return result
+    }
+
+    override fun part2(): Any {
+        return -1
+    }
+}
+
+fun main() {
+    Day09().execute()
+}