added lecture 13 code

syntax1/DIY/Map61B/ArrayMap.java

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+package Map61B;
+
+import org.junit.Assert.*;
+import java.util.List;
+import java.util.ArrayList;
+
+import static org.junit.Assert.*;
+
+/**
+ * An array based implementation of the Map61B class.
+ */
+public class ArrayMap<K, V> implements Map61B<K, V> {
+    public ArrayMap() {
+    }
+
+    /** Returns the index of the given key if it exists,
+     *  -1 otherwise. */
+    private int keyIndex(K key) {
+        return 0;    
+    }
+
+
+    public boolean containsKey(K key) {
+        return false;
+    }
+
+    public void put(K key, V value) {
+    }
+
+    public V get(K key) {
+        return false
+    }
+
+    public int size() {
+        return 0;
+    }
+
+    public List<K> keys() {
+        return null;
+    }
+
+    public static void main(String[] args) {
+        Map61B<String, Integer> m = new ArrayMap<String, Integer>();
+        m.put("horse", 3);
+        m.put("fish", 9);
+        m.put("house", 10);
+        int expected = 9;
+        assertEquals((Integer) expected, m.get("fish"));
+    }
+}

syntax1/DIY/Map61B/Map61B.java

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+package Map61B;
+import java.util.List;
+
+public interface Map61B<K, V> {
+    /* Returns true if this map contains a mapping for the specified key. */
+    boolean containsKey(K key);
+
+    /* Returns the value to which the specified key is mapped. No defined
+     * behavior if the key doesn't exist (ok to crash). */
+    V get(K key);
+
+    /* Returns the number of key-value mappings in this map. */
+    int size();
+
+    /* Associates the specified value with the specified key in this map. */
+    void put(K key, V value);
+
+    /* Returns a list of the keys in this map. */
+    List<K> keys();
+}

syntax1/DIY/Map61B/MapHelper.java

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+package Map61B;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+import java.util.List;
+
+/**
+ * Class to demonstrate how generic methods work in Java.
+ */
+public class MapHelper {
+    /* Write the following three methods:
+    /* get(Key) : Return item in map if it exists. */
+    /* maxKey() : Returns max of all keys. Works only if x and y have comparable data. */
+    /* allBark(): Makes all keys bark, but only works for Dogs. */
+
+    @Test
+    public void testGet() {
+        Map61B<String, Integer> m = new ArrayMap<String, Integer>();
+        m.put("horse", 3);
+        m.put("fish", 9);
+        m.put("house", 10);
+
+        /*Integer actual = MapHelper.get(m, "fish");
+        Integer expected = 9;
+        assertEquals(expected, actual);*/
+    }
+
+    @Test
+    public void testMaxKey() {
+        Map61B<String, Integer> m = new ArrayMap<String, Integer>();
+        m.put("horse", 3);
+        m.put("fish", 9);
+        m.put("house", 10);
+
+        /*String actual = MapHelper.maxKey(m);
+        String expected = "house";
+        assertEquals(expected, actual);*/
+    }    
+}