上传文件至 'w8'

w8/Pair.java

@@ -0,0 +1,65 @@
+import java.util.HashMap;
+import java.util.Map;
+
+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 Pair<V, K> swap() {
+        return new Pair<>(second, first);
+    }
+
+    @Override
+    public String toString() {
+        return "Pair{" + first + ", " + second + "}";
+    }
+}
+
+class Cache<K, V> {
+    private final Map<K, V> cache;
+
+    public Cache() {
+        this.cache = new HashMap<>();
+    }
+
+    public void put(K key, V value) {
+        cache.put(key, value);
+    }
+
+    public V get(K key) {
+        return cache.get(key);
+    }
+
+    public V remove(K key) {
+        return cache.remove(key);
+    }
+
+    public void clear() {
+        cache.clear();
+    }
+
+    public boolean containsKey(K key) {
+        return cache.containsKey(key);
+    }
+
+    public int size() {
+        return cache.size();
+    }
+
+    public boolean isEmpty() {
+        return cache.isEmpty();
+    }
+}