(HashSet) Решение задачи 6.

src/com/school/faang/hashset/задача_6/Solution.java

@@ -1,7 +1,53 @@
 package com.school.faang.hashset.задача_6;
 
+import java.util.*;
+
 public class Solution {
+    static class RecommendationEngine {
+        private HashMap<String, HashSet<String>> videosByChannel;
+
+        public RecommendationEngine(HashMap<String, HashSet<String>> videosByChannel) {
+            this.videosByChannel = videosByChannel;
+        }
+
+        void addVideo(String channelName, String videoTitle) {
+            if (videosByChannel.containsKey(channelName)) {
+                videosByChannel.get(channelName).add(videoTitle);
+            }
+            else {
+                videosByChannel.put(channelName, new HashSet<>(List.of(videoTitle)));
+            }
+        }
+
+        HashSet<String> getVideos(String channelName) {
+            return videosByChannel.get(channelName);
+        }
+    }
+
+    public List<String> generateFeed(HashSet<String> subscriptions, HashSet<String> watchHistory, RecommendationEngine engine) {
+
+        HashSet<String> recommendations = new HashSet<>();
+
+        for (String channel : subscriptions) {
+            recommendations.addAll(engine.getVideos(channel));
+        }
+
+        recommendations.removeAll(watchHistory);
+
+        ArrayList<String> finalSeed = new ArrayList<>(recommendations);
+        Collections.shuffle(finalSeed);
+
+        return finalSeed;
+    }
     public static void main(String[] args) {
+        Solution solution = new Solution();
+        RecommendationEngine engine = new RecommendationEngine(new HashMap<>());
+        engine.addVideo("MrBeast","100 людей в кругу");
+        engine.addVideo("Собака","Один день из моей жизни");
+        engine.addVideo("MrBeast", "7 дней на плоту");
+        engine.addVideo("FAANG School", "HashMap в Java");
+        engine.addVideo("FAANG School", "HashSet в Java");
 
+        System.out.println(solution.generateFeed(new HashSet<>(engine.videosByChannel.keySet()), new HashSet<>(List.of("HashMap в Java")), engine));
     }
 }