Merge remote-tracking branch 'upstream/master'

chzh55 · chzh55 · commit 7f79869481a0 · 2017-04-28T09:40:28.000+08:00
diff --git a/liuxin/data-structure/answer/src/com/coding/basic/queue/CircleQueue.java b/liuxin/data-structure/answer/src/com/coding/basic/queue/CircleQueue.java
@@ -1,33 +1,46 @@
 package com.coding.basic.queue;
 
 public class CircleQueue <E> {
-	
-	private final static int DEFAULT_SIZE = 10;
-	
+
 	//用数组来保存循环队列的元素
-	private Object[] elementData = new Object[DEFAULT_SIZE] ;
-	
+	private Object[] elementData ;
+	int size = 0;
 	//队头
 	private int front = 0;  
 	//队尾  
 	private int rear = 0;
 	
+	public CircleQueue(int capacity){
+		elementData = new Object[capacity];
+	}
 	public boolean isEmpty() {
-		return false;
+		return front == rear;
         
     }
-
+	
+	public boolean isFull(){
+		return  size == elementData.length;
+	}
     public int size() {
-        return -1;
+        return size;
     }
 
-    
-
     public void enQueue(E data) {
-        
+        if(isFull()){
+        	throw new RuntimeException("The queue is full");
+        }
+        elementData[rear++] = data;
+        size++;
     }
 
     public E deQueue() {
-        return null;
+        if(isEmpty()){
+        	throw new RuntimeException("The queue is empty");
+        }
+        E data = (E)elementData[front];
+        elementData[front] = null;
+        front = (front+1) % elementData.length;
+        size --;
+        return data;
     }
 }
diff --git a/liuxin/data-structure/answer/src/com/coding/basic/queue/CircleQueueTest.java b/liuxin/data-structure/answer/src/com/coding/basic/queue/CircleQueueTest.java
@@ -0,0 +1,44 @@
+package com.coding.basic.queue;
+
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+
+
+public class CircleQueueTest {
+
+	@Before
+	public void setUp() throws Exception {
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void test() {
+		CircleQueue<String> queue = new CircleQueue<String>(5);		
+		Assert.assertTrue(queue.isEmpty());
+		Assert.assertFalse(queue.isFull());
+		
+		queue.enQueue("a");
+		queue.enQueue("b");
+		queue.enQueue("c");
+		queue.enQueue("d");
+		queue.enQueue("e");
+		
+		Assert.assertTrue(queue.isFull());
+		Assert.assertFalse(queue.isEmpty());
+		Assert.assertEquals(5, queue.size());
+		
+		Assert.assertEquals("a", queue.deQueue());
+		Assert.assertEquals("b", queue.deQueue());
+		Assert.assertEquals("c", queue.deQueue());
+		Assert.assertEquals("d", queue.deQueue());
+		Assert.assertEquals("e", queue.deQueue());
+		
+	}
+
+}
