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Coding Kata: Implement LRU

Build a thread-safe LRU with LinkedHashMap or a doubly-linked list — the pattern question paid courses assign.

AdvancedPro14 min readBy Kishore BhosaleReviewed
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Coding kata · Implement a fixed-size LRU cache

~14 min · type in your IDE or JShell, then check the answer

Complete an LRU cache with capacity 3 using LinkedHashMap. After each access, the least recently used key should be evicted when size exceeds capacity.

Java
public class LruCache<K, V> extends LinkedHashMap<K, V> {
  private final int capacity;

  public LruCache(int capacity) {
      // TODO: call super with accessOrder = true
      this.capacity = capacity;
  }

  @Override
  protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
      // TODO: return true when size() > capacity
      return false;
  }
}
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