Решение задачи - 4

src/com/school/faang/hashset/задача_4/ChannelManager.java

@@ -0,0 +1,34 @@
+package com.school.faang.hashset.задача_4;
+
+import java.util.HashMap;
+import java.util.HashSet;
+
+public class ChannelManager {
+
+    private HashSet<String> members;
+
+    private HashMap<String, String> memberRoles;
+
+    public ChannelManager(HashSet<String> members, HashMap<String, String> memberRoles) {
+        this.members = members;
+        this.memberRoles = memberRoles;
+    }
+
+    protected void addUser(String userId, String role) {
+        members.add(userId);
+        memberRoles.putIfAbsent(userId, role);
+    }
+
+    protected void removeUser(String userId) {
+        members.remove(userId);
+        memberRoles.remove(userId);
+    }
+
+    protected String getRole(String userId) {
+        return memberRoles.getOrDefault(userId, "Данный пользователь не является участником.");
+    }
+
+    protected boolean hasUser(String userId) {
+        return members.contains(userId);
+    }
+}

src/com/school/faang/hashset/задача_4/Solution.java

@@ -1,7 +1,37 @@
 package com.school.faang.hashset.задача_4;
 
+import java.util.HashMap;
+import java.util.HashSet;
+
 public class Solution {
     public static void main(String[] args) {
+        printInfo();
+    }
+
+    private static void printInfo() {
+        HashMap<String, String> memberRoles = new HashMap<>();
+
+        HashSet<String> members = new HashSet<>();
+
+        ChannelManager manager = new ChannelManager(members, memberRoles);
+
+        manager.addUser("1", "админ");
+        manager.addUser("2", "модератор");
+        manager.addUser("3", "участник");
+        manager.addUser("4", "участник");
+        manager.addUser("5", "модератор");
+        manager.addUser("6", "участник");
+        manager.addUser("7", "участник");
+
+        System.out.println(manager.hasUser("3"));
+        System.out.println(manager.hasUser("7"));
+        System.out.println(manager.hasUser("9"));
+
+        System.out.println(manager.getRole("1"));
+        System.out.println(manager.getRole("9"));
 
+        manager.removeUser("5");
+        System.out.println(manager.hasUser("5"));
+        System.out.println(manager.getRole("5"));
     }
 }