Updates part 2

Author: suggitpe

2024/src/main/kotlin/org/suggs/aoc2024/Day02RedNosedReports.kt

@@ -8,12 +8,29 @@ object Day02RedNosedReports {
     private val log = LoggerFactory.getLogger(this::class.java)
 
     fun countNumberOfSafeReportsFrom(data: List<String>) =
-        data.count { isSafe(it.split(" ").map { it.toInt() }.zipWithNext().map { it.first - it.second }) }
-
-    private fun isSafe(lineDeltas: List<Int>) = allInRange(lineDeltas) && sameDirection(lineDeltas)
+        data.count { isSafeLine(it.split(" ").map { it.toInt() }) }
 
+    private fun isSafeLine(line: List<Int>) = isSafeDeltas(line.zipWithNext().map { it.second - it.first })
+    private fun isSafeDeltas(lineDeltas: List<Int>) = allInRange(lineDeltas) && allSameDirection(lineDeltas)
     private fun allInRange(lineDeltas: List<Int>) = lineDeltas.all { abs(it) in 1..3 }
+    private fun allSameDirection(lineDeltas: List<Int>) = lineDeltas.all { it > 0 } || lineDeltas.all { it < 0 }
+
+    fun countNumberOfDampenedSafeReportsFrom(data: List<String>): Int =
+        data.count { isDampenedSafeLine(it.split(" ").map { it.toInt() }) }
+
+    private fun isDampenedSafeLine(line: List<Int>): Boolean {
+        return if(isSafeLine(line)) true
+        else findSubLisThatIsSafe(line)
+    }
+
+    private fun findSubLisThatIsSafe(line: List<Int>): Boolean {
+        for(i in line.indices) {
+            val mutated = line.toMutableList()
+            mutated.removeAt(i)
+            if(isSafeLine(mutated)) return true
+        }
+        return false
+    }
 
-    private fun sameDirection(lineDeltas: List<Int>) = lineDeltas.all { it > 0 } || lineDeltas.all { it < 0 }
 
 }

2024/src/test/kotlin/org/suggs/aoc2024/Day02RedNosedReportsTest.kt

@@ -5,6 +5,7 @@ import org.junit.jupiter.api.Disabled
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
 import org.suggs.adventofcode.Util.getFileLinesFrom
+import org.suggs.aoc2024.Day02RedNosedReports.countNumberOfDampenedSafeReportsFrom
 import org.suggs.aoc2024.Day02RedNosedReports.countNumberOfSafeReportsFrom
 
 @DisplayName("Red-Nosed Reports")
@@ -21,6 +22,17 @@ class Day02RedNosedReportsTest {
         countNumberOfSafeReportsFrom(largeData) shouldBe 123
     }
 
+    @Test
+    fun `counts number of dampened safe reports from a short list`() {
+        countNumberOfDampenedSafeReportsFrom(smallData) shouldBe 4
+    }
+
+    @Test
+    @Disabled
+    fun `counts number of dampened safe reports from a larger  list`() {
+        countNumberOfDampenedSafeReportsFrom(largeData) shouldBe 123
+    }
+
     private val largeData = getFileLinesFrom("day02-input.txt")
     private val smallData = """7 6 4 2 1
 1 2 7 8 9