上传文件至 'W8'

W8/Cache.java

@@ -0,0 +1,65 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class Cache<K, V> {
+    private Map<K, V> cacheMap;
+    private int maxSize;
+
+    public Cache() {
+        this.cacheMap = new HashMap<>();
+        this.maxSize = Integer.MAX_VALUE;
+    }
+
+    public Cache(int maxSize) {
+        this.cacheMap = new HashMap<>();
+        this.maxSize = maxSize;
+    }
+
+    public void put(K key, V value) {
+        if (cacheMap.size() >= maxSize) {
+            K firstKey = cacheMap.keySet().iterator().next();
+            cacheMap.remove(firstKey);
+        }
+        cacheMap.put(key, value);
+    }
+
+    public V get(K key) {
+        return cacheMap.get(key);
+    }
+
+    public boolean containsKey(K key) {
+        return cacheMap.containsKey(key);
+    }
+
+    public V remove(K key) {
+        return cacheMap.remove(key);
+    }
+
+    public int size() {
+        return cacheMap.size();
+    }
+
+    public void clear() {
+        cacheMap.clear();
+    }
+
+    @Override
+    public String toString() {
+        return cacheMap.toString();
+    }
+
+    public static void main(String[] args) {
+        Cache<String, Integer> cache = new Cache<>(3);
+        cache.put("A", 1);
+        cache.put("B", 2);
+        cache.put("C", 3);
+        System.out.println("Cache after adding A,B,C: " + cache);
+        
+        cache.put("D", 4);
+        System.out.println("Cache after adding D (maxSize=3): " + cache);
+        
+        System.out.println("Get B: " + cache.get("B"));
+        System.out.println("Contains C: " + cache.containsKey("C"));
+        System.out.println("Size: " + cache.size());
+    }
+}

W8/Pair.java

@@ -0,0 +1,43 @@
+public class Pair<K, V> {
+    private K first;
+    private V second;
+
+    public Pair(K first, V second) {
+        this.first = first;
+        this.second = second;
+    }
+
+    public K getFirst() {
+        return first;
+    }
+
+    public V getSecond() {
+        return second;
+    }
+
+    public void setFirst(K first) {
+        this.first = first;
+    }
+
+    public void setSecond(V second) {
+        this.second = second;
+    }
+
+    public void swap() {
+        Object temp = first;
+        first = (K) second;
+        second = (V) temp;
+    }
+
+    @Override
+    public String toString() {
+        return "(" + first + ", " + second + ")";
+    }
+
+    public static void main(String[] args) {
+        Pair<String, Integer> pair = new Pair<>("Hello", 42);
+        System.out.println("Before swap: " + pair);
+        pair.swap();
+        System.out.println("After swap: " + pair);
+    }
+}