Code after lecture

00/DoggieAnimation.java

@@ -4,7 +4,7 @@ public class DoggieAnimation {
         StdDraw.setCanvasSize(1024, 768);
         StdDraw.setScale(-1024, 1024);
 
-        IntBag bag = null;
+        IntBag bag = new IntBag(1, 10);
 
         // Add each picture once
         for (int i = 1; i <= 10; i++) {
@@ -22,7 +22,7 @@ public class DoggieAnimation {
             // draw it
             StdDraw.picture(0, 0, pic);
             // pause
-            StdDraw.pause(2000);
+            StdDraw.pause(20);
             System.out.println(pic);
         }
     }

00/IntBag.java

+import java.util.ArrayList;
+import java.util.Random;
+
 /**
  * An IntBag represents a multiset of integers between min and max.
  * That is, each number between min and max can occur some non-negative
  * number of times in a particular IntBag.
  */
 public class IntBag {
+    // arrays
+    // lists
+    // dictionaries
+    // sets
+    // tuples
+
+    private final ArrayList<Integer> list;
+    private final int min;
+    private final int max;
 
     // constructors in java are like __init__ in python
     public IntBag(int min, int max) {
-
+        this.list = new ArrayList<>();
+        this.min = min;
+        this.max = max;
     }
 
     /**
@@ -15,7 +29,7 @@ public class IntBag {
      * @param value the value to be added
      */
     public void add(int value) {
-
+        this.list.add(value);
     }
 
     /**
@@ -24,7 +38,7 @@ public class IntBag {
      * @return true iff the bag is empty
      */
     public boolean isEmpty() {
-        return false;
+        return this.list.isEmpty();
     }
 
     /**
@@ -33,6 +47,7 @@ public class IntBag {
      * @return the element picked from the bag
      */
     public int pick() {
-        return -1;
+        Random r = new Random();
+        return this.list.get(r.nextInt(min - 1, max));
     }
 }