2024 Day 1 part 1

Author: leibi

src/main/java/net/leibi/adventofcode2024/day1/Day1.java

@@ -0,0 +1,41 @@
+package net.leibi.adventofcode2024.day1;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Day1 {
+
+
+    public long part1(String input) {
+        var lists = getListOfListsFromInput(input);
+        return getSumOfDistances(lists.get(0), lists.get(1));
+    }
+
+
+    public List<List<Integer>> getListOfListsFromInput(String input) {
+        var left = new ArrayList<Integer>();
+        var right = new ArrayList<Integer>();
+        input.lines().forEach(line -> {
+            final var split = line.split("\\s+");
+            left.add(Integer.valueOf(split[0]));
+            right.add(Integer.valueOf(split[1]));
+        });
+
+        return List.of(left, right);
+    }
+
+    public Integer getSumOfDistances(List<Integer> left, List<Integer> right) {
+        if (left.size() != right.size()) throw new RuntimeException("list sizes differ");
+
+        left.sort(Integer::compareTo);
+        right.sort(Integer::compareTo);
+
+        Integer sum = 0;
+        for (var i = 0; i < left.size(); i++) {
+            sum += Math.abs(left.get(i) - right.get(i));
+        }
+
+        return sum;
+    }
+
+}