feat: Comparator

src/main/java/eu/ztsh/training/hackerrank/datastructures/comparator/Solution.java

@@ -0,0 +1,52 @@
+package eu.ztsh.training.hackerrank.datastructures.comparator;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Scanner;
+
+/**
+ * source: <a href="https://www.hackerrank.com/challenges/java-comparator">Java Comparator</a>
+ */
+
+class Checker implements Comparator<Player> {
+
+    @Override
+    public int compare(Player o1, Player o2) {
+        var points = o2.score - o1.score;
+        return points != 0 ? points : o1.name.compareTo(o2.name);
+    }
+
+}
+
+// Hackerrank code below (slightly modified)
+public class Solution {
+
+    public static void main(String[] args) {
+        Scanner scan = new Scanner(System.in);
+        int n = scan.nextInt();
+
+        Player[] player = new Player[n];
+        Checker checker = new Checker();
+
+        for (int i = 0; i < n; i++) {
+            player[i] = new Player(scan.next(), scan.nextInt());
+        }
+        scan.close();
+
+        Arrays.sort(player, checker);
+        Arrays.stream(player).forEach(value -> System.out.printf("%s %s%s", value.name, value.score, System.lineSeparator()));
+    }
+
+}
+
+class Player {
+
+    String name;
+    int score;
+
+    Player(String name, int score) {
+        this.name = name;
+        this.score = score;
+    }
+
+}

src/test/java/eu/ztsh/training/hackerrank/datastructures/comparator/SolutionTest.java

@@ -0,0 +1,39 @@
+package eu.ztsh.training.hackerrank.datastructures.comparator;
+
+import eu.ztsh.training.hackerrank.HackerRankTest;
+import eu.ztsh.training.hackerrank.SolutionClassDescription;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+@DisplayName("HackerRank challenges: Java Comparator")
+class SolutionTest extends HackerRankTest {
+
+    @Test
+    public void testCase0() {
+        simpleAssert(
+                List.of(
+                        "5",
+                        "amy 100",
+                        "david 100",
+                        "heraldo 50",
+                        "aakansha 75",
+                        "aleksa 150"
+                ),
+                List.of(
+                        "aleksa 150",
+                        "amy 100",
+                        "david 100",
+                        "aakansha 75",
+                        "heraldo 50"
+                )
+        );
+    }
+
+    @Override
+    protected SolutionClassDescription getSolutionClassDescription() {
+        return new SolutionClassDescription(Solution.class);
+    }
+
+}