Day01

days/src/main/kotlin/Day01.kt

@@ -0,0 +1,33 @@
+package be.vandewalleh.aoc.days
+
+import be.vandewalleh.aoc.utils.Resources
+
+object Day01 {
+
+    fun part1(list: List<Int>): Int? {
+        list.forEach { a ->
+            list.forEach { b ->
+                if (a + b == 2020) return a * b
+            }
+        }
+        return null
+    }
+
+    fun part2(list: List<Int>): Int? {
+        list.forEach { a ->
+            list.forEach { b ->
+                list.forEach { c ->
+                    if (a + b + c == 2020) return a * b * c
+                }
+            }
+        }
+        return null
+    }
+
+}
+
+fun main() {
+    val input = Resources.ints("day01.txt").toList()
+    println(Day01.part1(input))
+    println(Day01.part2(input))
+}

days/src/main/resources/day01.txt

@@ -0,0 +1,200 @@
+1779
+1737
+1537
+1167
+1804
+1873
+1894
+1446
+1262
+1608
+1430
+1421
+1826
+1718
+1888
+1314
+1844
+248
+1812
+1627
+1605
+1641
+1126
+1051
+1839
+1067
+1685
+1800
+1383
+1415
+1781
+1372
+1711
+1687
+1357
+1603
+1899
+1856
+1240
+1872
+1483
+1624
+1358
+1168
+1238
+1585
+1159
+1409
+1615
+1258
+1412
+1468
+1912
+1840
+1681
+1700
+1031
+1757
+1911
+1096
+1239
+1331
+1881
+1304
+1694
+1705
+1680
+820
+1744
+1245
+1922
+1545
+1335
+1852
+1318
+1565
+1505
+1535
+1536
+1758
+1508
+1453
+1957
+1375
+1647
+1531
+1261
+1202
+1701
+1562
+1933
+1293
+1828
+334
+1714
+1931
+1385
+1294
+1469
+1629
+1842
+1730
+1534
+1544
+1946
+1805
+1188
+1684
+1875
+1623
+1248
+1347
+2006
+1191
+1037
+1387
+1903
+1746
+16
+952
+1246
+384
+1518
+1738
+1269
+1747
+1423
+1764
+1666
+1999
+1776
+1673
+1350
+1698
+2004
+1235
+1719
+1131
+1671
+1334
+1556
+1299
+1569
+1523
+1655
+1189
+1023
+1264
+1821
+1639
+1114
+1391
+1154
+1225
+1906
+1481
+1728
+1309
+1682
+1662
+1017
+1952
+1948
+2010
+1809
+1394
+1039
+1493
+1509
+1628
+1401
+1515
+1497
+1164
+1829
+1452
+1706
+1919
+1831
+1643
+1849
+1558
+1162
+1328
+1432
+680
+1169
+1393
+1646
+1161
+1104
+1678
+1477
+1824
+1353
+1260
+1736
+1777
+1658
+1715

days/src/test/kotlin/Day01Test.kt

@@ -0,0 +1,21 @@
+package be.vandewalleh.aoc.days
+
+import be.vandewalleh.aoc.utils.Resources
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+
+class Day01Test {
+
+    private val input = Resources.ints("day01.txt").toList()
+
+    @Test
+    fun `part1 result`() {
+        assertThat(Day01.part1(input)).isEqualTo(32064)
+    }
+
+    @Test
+    fun `part2 result`() {
+        assertThat(Day01.part2(input)).isEqualTo(193598720)
+    }
+
+}

days/src/test/resources/junit-platform.properties

@@ -0,0 +1,4 @@
+junit.jupiter.testinstance.lifecycle.default=per_class
+junit.jupiter.execution.parallel.enabled=true
+junit.jupiter.execution.parallel.mode.default=same_thread
+junit.jupiter.execution.parallel.mode.classes.default=concurrent

utils/src/main/kotlin/be/vandewalleh/aoc/utils/Resources.kt

@@ -22,6 +22,7 @@ object Resources {
 
     fun text(name: String) = path(name).text()
     fun lines(name: String) = path(name).lines()
+    fun ints(name: String) = lines(name).map { it.toInt() }
     fun csv(name: String) = path(name).text().splitToSequence(",")
     fun csvLong(name: String) = csv(name).map { it.toLong() }
 }