feat:w8

w8/Cache.java

@@ -0,0 +1,29 @@
+package Homework;
+import java.util.HashMap;
+import java.util.Map;
+public class Cache<K,V> {
+    private final Map<K,V> cacheMap;
+    public Cache(){
+        cacheMap=new HashMap<>();
+    }
+    public void put(K key,V value){
+        cacheMap.put(key,value);
+    }
+    public V get(K key){
+        return cacheMap.get(key);
+    }
+    public void remove(K key){
+        cacheMap.remove(key);
+    }
+    public void clear(){
+        cacheMap.clear();
+    }
+    public int size(){
+        return cacheMap.size();
+    }
+    public static void main(String[] args) {
+       Cache<String,String>cache=new Cache<>();
+       cache.put("1","one");
+       System.out.println(cache.get("1"));
+    }
+}

w8/Pair.java

@@ -0,0 +1,41 @@
+package Homework;
+
+public class Pair<K,V> {
+    private K key;
+    private V value;
+    
+    public Pair(K key,V value){
+        this.key=key;
+        this.value=value;
+    }
+    
+    public K getKey(){
+        return key;
+    }
+    
+    public V getValue(){
+        return value;
+    }
+    
+    public void setKey(K key){
+        this.key=key;
+    }
+    
+    public void setValue(V value){
+        this.value=value;
+    }
+
+    public static <K,V> Pair<V,K> swap(Pair<K,V>pair){
+        return new Pair<>(pair.getValue(),pair.getKey());
+    }
+
+    public static void main(String[] args) {
+        Pair<String,Integer> p=new Pair<>("hello",10);
+        System.out.println(p.getKey());
+        System.out.println(p.getValue());
+        p.setKey("world");
+        p.setValue(20);
+        System.out.println(p.getKey());
+        System.out.println(p.getValue());
+    }
+}