21. asan

List.java

@@ -0,0 +1,90 @@
+
+public class List<T>
+{
+    private Node<T> first;
+    
+    public List() {
+        first = null;
+    }
+    
+    public boolean isEmpty() {
+        if (first == null) return true;
+        return false;
+    }
+    
+    public int size() {
+        Node<T> current = first;
+        int count = 0;
+        
+        while (current != null) {
+            count++;
+            current = current.next;
+        }
+        
+        return count;
+    }
+    
+    public T get(int n) {
+        Node<T> current = first;
+        
+        for (int i = 0; i < n; i++) {
+            if (current == null) return null;
+            current = current.next;
+        }
+        
+        if (current == null) return null;
+        return current.wert;
+    }
+    
+    public void add(T val) {
+        Node<T> neu = new Node<T>();
+        neu.wert = val;
+        
+        if (first == null) {
+            first = neu;
+        } else {
+            Node<T> current = first;
+            while (current.next != null) {
+                current = current.next;
+            }
+            current.next = neu;
+        }
+    }
+    
+    public void add(int n, T val) {
+        if (n >=size()) {
+            add(val);
+            return;
+        }
+        Node<T> neu = new Node<T>();
+
+        neu.wert = val;
+        
+        if (n==0){
+            neu.next = first;
+            first = neu;
+            return;
+        }
+        
+        for (int i = 0; i < n-1; i++){
+            current = current.next;
+        }
+        neu.next = current.next;
+        current.next = neu;
+        
+    }
+    
+    public boolean contains(T val) {
+        Node<T> current = first;
+        
+        while (current != null) {
+            if (current.wert.equals(val)) return true;
+        }
+        
+        return false;
+    }
+    
+    public T remove(int n) {
+        
+    }
+}