day 5 puzzle 1

src/day5/Puzzle1.scala

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+package day5
+
+import scala.io.{BufferedSource, Source}
+
+object Puzzle1 {
+  case class Range(startSrc: Long, startDst: Long, length: Long)
+  var forwardingTables: Array[Array[Range]] = Array.empty
+  var seeds: Array[Long] = Array.empty
+  def loadInput(path: String): Unit = {
+    val source: BufferedSource = Source.fromFile(path)
+
+    val almanac: String = source.getLines().mkString("\n")
+    val tables: Array[String] = almanac.split("\n\n")
+
+    forwardingTables = new Array(tables.length - 1)
+    seeds = tables(0).substring(7).split(" ").map(s => s.toLong)
+
+    for (i: Int <- 1 until tables.length) {
+      val lines: Array[String] = tables(i).split(":\n")(1).split("\n")
+      val table: Array[Range] = new Array(lines.length)
+      for ((line: String, j: Int) <- lines.zipWithIndex) {
+        val values: Array[Long] = line.split(" ").map(v => v.toLong)
+        table(j) = Range(values(1), values(0), values(2))
+      }
+      forwardingTables(i-1) = table
+    }
+
+    source.close()
+  }
+
+  def sortTables(): Unit = {
+    for (table: Array[Range] <- forwardingTables) {
+      var changed: Boolean = false
+      do {
+        changed = false
+        for (i: Int <- 0 until table.length-1) {
+          if (table(i).startSrc >= table(i + 1).startSrc + table(i + 1).length) {
+            changed = true
+            val range: Range = table(i)
+            table(i) = table(i + 1)
+            table(i + 1) = range
+          }
+        }
+      } while (changed)
+    }
+  }
+  def map(seed: Long): Long = {
+    var value: Long = seed
+    for (i: Int <- forwardingTables.indices) {
+      value = forward(value, i)
+    }
+    return value
+  }
+
+  def forward(value: Long, tableI: Int): Long = {
+    for (range: Range <- forwardingTables(tableI)) {
+      if (value >= range.startSrc) {
+        if (value < range.startSrc + range.length) {
+          return value - range.startSrc + range.startDst
+        }
+      } else {
+        return value
+      }
+    }
+    return value
+  }
+  def solve(path: String): Long = {
+    loadInput(path)
+    sortTables()
+    var smallest: Long = -1
+    for (seed: Long <- seeds) {
+      val location: Long = map(seed)
+      if (smallest == -1 || location < smallest) {
+        smallest = location
+      }
+    }
+    return smallest
+  }
+  def main(args: Array[String]): Unit = {
+    val solution: Long = solve("res/day5/input1.txt")
+    println(solution)
+  }
+}