added Graph

Author: khalil2535

data_structures/graph/UnDirectedGraph.java

@@ -0,0 +1,99 @@
+package data_structures.graph;
+
+import java.util.ArrayList;
+
+/**
+ *
+ * @author khalil2535
+ * @param <E>
+ */
+public class UnDirectedGraph<E> {
+
+    ArrayList<vertix<E>> vertixes;
+
+    public UnDirectedGraph() {
+        this.vertixes = new ArrayList<>();
+    }
+
+    /**
+     *
+     * @param entity
+     * @return true if added or false if not
+     */
+    public boolean addEntity(E entity) {
+        if (!contatin(entity)) {
+            return vertixes.add(new vertix<>(entity));
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     *
+     * @param entity1
+     * @param entity2
+     * @return true if added or false if not
+     */
+    public boolean addConnection(E entity1, E entity2) {
+        if (contatin(entity1) && contatin(entity2)) {
+            return vertixOf(entity1).connect(vertixOf(entity2));
+        }
+        return false;
+    }
+
+    /**
+     *
+     * @param entity
+     * @return true if contains or false if not
+     */
+    public boolean contatin(E entity) {
+        return vertixes.stream().anyMatch((v) -> (v.item == entity));
+    }
+
+    /**
+     *
+     * @param entity
+     * @return the vertix for the entity
+     */
+    private vertix<E> vertixOf(E entity) {
+        for (vertix<E> vertix : vertixes) {
+            if (vertix.item == entity) {
+                return vertix;
+            }
+        }
+        return null;
+    }
+
+    class vertix<E> {
+
+        E item;
+        ArrayList<vertix<E>> connections;
+
+        public vertix(E entity) {
+            this.item = entity;
+            connections = new ArrayList<>();
+        }
+
+        public boolean connect(vertix<E> v) {
+            if (connections.contains(v)) {
+                return false;
+            } else {
+                connections.add(v);
+                v.connections.add(this);
+                return true;
+            }
+        }
+
+        @Override
+        public String toString() {
+            return item.toString();
+        }
+
+    }
+
+    @Override
+    public String toString() {
+        return vertixes.toString();
+    }
+
+}

data_structures/graph/tests/GraphTest.java

@@ -0,0 +1,22 @@
+package data_structures.graph.tests;
+
+import data_structures.graph.UnDirectedGraph;
+
+/**
+ *
+ * @author khalil2535
+ */
+public class GraphTest {
+
+    public static void main(String[] args) {
+        UnDirectedGraph g = new UnDirectedGraph();
+        Object A = "A";
+        Object B = "B";
+        g.addEntity(A);
+        g.addEntity(B);
+        g.addConnection(A, B);
+        System.out.println(g);
+
+    }
+
+}

data_structures/queues/Queue.java

@@ -7,7 +7,7 @@ public class Queue<T> {
     private int nitems;
     private int rear;
     private int front;
-    private T[] array;
+    private final T[] array;
 
     public Queue(int capacity) {
         array = (T[]) new Object[capacity];