Data commit

Task/Top-rank-per-group/Java/top-rank-per-group.java

@@ -0,0 +1,49 @@
+import java.io.File;
+import java.util.*;
+
+public class TopRankPerGroup {
+
+    private static class Employee {
+        final String name;
+        final String id;
+        final String department;
+        final int salary;
+
+        Employee(String[] rec) {
+            name = rec[0];
+            id = rec[1];
+            salary = Integer.parseInt(rec[2]);
+            department = rec[3];
+        }
+
+        @Override
+        public String toString() {
+            return String.format("%s %s %d %s", id, name, salary, department);
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        int N = args.length > 0 ? Integer.parseInt(args[0]) : 3;
+
+        Map<String, List<Employee>> records = new TreeMap<>();
+        try (Scanner sc = new Scanner(new File("data.txt"))) {
+            while (sc.hasNextLine()) {
+                String[] rec = sc.nextLine().trim().split(", ");
+
+                List<Employee> lst = records.get(rec[3]);
+                if (lst == null) {
+                    lst = new ArrayList<>();
+                    records.put(rec[3], lst);
+                }
+                lst.add(new Employee(rec));
+            }
+        }
+
+        records.forEach((key, val) -> {
+            System.out.printf("%nDepartment %s%n", key);
+            val.stream()
+                .sorted((a, b) -> Integer.compare(b.salary, a.salary))
+                .limit(N).forEach(System.out::println);
+        });
+    }
+}