uebung_02: complete IntArrayList with get, size, sort, remove and finish add

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

uebung_02/src/util/IntArrayList.java

@@ -14,7 +14,42 @@ public class IntArrayList {
         }
         else {
             int[] arrTemp = new int[lenght*2];
-            
+            System.arraycopy(arr, 0, arrTemp, 0, lenght);
+            arr = arrTemp;
+            lenght = lenght * 2;
+            arr[lastUnfilledPos] = a;
+            lastUnfilledPos ++;
         }
     }
+
+    public int get(int pos){
+        if (pos < 0 || pos >= lastUnfilledPos){
+            return -1;
+        }
+        return arr[pos];
+    }
+
+    public int size(){
+        return lastUnfilledPos;
+    }
+
+    public void sort(){
+        int[] view = new int[lastUnfilledPos];
+        System.arraycopy(arr, 0, view, 0, lastUnfilledPos);
+        Sorter sorter = new Sorter();
+        sorter.mergeSort(view);
+        System.arraycopy(view, 0, arr, 0, lastUnfilledPos);
+    }
+
+    public int remove(int pos){
+        if (pos < 0 || pos >= lastUnfilledPos){
+            return -1;
+        }
+        int removed = arr[pos];
+        for (int i = pos; i < lastUnfilledPos -1; i++){
+            arr[i] = arr[i+1];
+        }
+        lastUnfilledPos --;
+        return removed;
+    }
 }