day4

src/main/kotlin/Day4.kt

@@ -0,0 +1,38 @@
+import java.io.File
+import java.lang.Integer.max
+import java.lang.Integer.min
+
+fun main() {
+    println("Hello day4!")
+    solveDay4()
+}
+
+fun solveDay4() {
+    val part1 = File("input/day4").readLines()
+        .count { conpleteOverlap(it) }
+    println(part1)
+
+    val part2 = File("input/day4").readLines()
+        .count { partialOverlap(it) }
+    println(part2)
+}
+
+fun conpleteOverlap(line: String): Boolean {
+    val number = "(\\d+)-(\\d+),(\\d+)-(\\d+)".toRegex()
+    val l = number.find(line)!!.groupValues.stream().skip(1).map { Integer.valueOf(it) }.toList()
+
+    val min = min(l[0], l[2])
+    val max = max(l[1], l[3])
+
+    return (min == l[0] && max == l[1]) || (min == l[2] && max == l[3])
+}
+
+fun partialOverlap(line: String): Boolean {
+    val number = "(\\d+)-(\\d+),(\\d+)-(\\d+)".toRegex()
+    val l = number.find(line)!!.groupValues.stream().skip(1).map { Integer.valueOf(it) }.toList()
+
+    val max = max(l[0], l[2])
+    val min = min(l[1], l[3])
+
+    return min >= max
+}