Queue(链式队列)
Queue
package Queue; class QNode<T> { T data; QNode<T> next; public boolean equals(QNode<T> node) { if (data.equals(node.data)) { return true; } return false; } public int hashCode() { return data.hashCode(); } } class LinkQueue<T> { QNode<T> front; QNode<T> rear; int size; public LinkQueue() { } public void init() { front = new QNode<T>(); rear = front; front.next = null; size = 0; } public void destroy() { } //插入队尾 public void enQueue(T key) { QNode<T> node = new QNode<T>(); node.next = null; node.data = key; // 队列为空时添加的node if (front.next == null) { front.next = node; } rear.next = node;//修改间接后继 rear = node;//修改直接后继 } //删除队头 public QNode<T> deQueue() { QNode<T> node = new QNode<T>(); if (!isEmpty()) { node = front.next; front.next = node.next; System.out.println("删除的value值为:" + node.data); //删除队列中最后一个元素的处理 if (rear == node) rear = front; return node; } return null; } public boolean isEmpty() { if (front == rear) return true; return false; } public void queueTraverse() { if (isEmpty()) { System.out.print("当前队列为空"); } else { //与双向列表有所区别 QNode<T> node = front; while (node.next != null) { System.out.print(node.next.data + "-->"); node = node.next; } System.out.println(); } } } public class QueueTest { public static void main(String[] args) { LinkQueue<Integer> queue = new LinkQueue<Integer>(); queue.init(); /************************ * 入队列操作 * **********************/ queue.enQueue(1); queue.enQueue(2); queue.enQueue(3); queue.enQueue(4); queue.queueTraverse(); /************************ * 出队列操作 * **********************/ queue.deQueue(); queue.deQueue(); queue.deQueue(); queue.deQueue(); queue.queueTraverse(); } }
Queue(顺序队列)
Queue2
package Queue; //顺序队列 //////////////////////////////////////////////////////////////// class Queue { private int maxSize; private long[] queArray; private int front; private int rear; private int nItems; //-------------------------------------------------------------- public Queue(int s) // constructor { maxSize = s; queArray = new long[maxSize]; front = 0; rear = -1; nItems = 0; } //-------------------------------------------------------------- public void insert(long j) // put item at rear of queue { if (rear == maxSize - 1) // deal with wraparound rear = -1; queArray[++rear] = j; // increment rear and insert nItems++; // one more item } //-------------------------------------------------------------- public long remove() // take item from front of queue { long temp = queArray[front++]; // get value and incr front if (front == maxSize) // deal with wraparound front = 0; nItems--; // one less item return temp; } //-------------------------------------------------------------- public long peekFront() // peek at front of queue { return queArray[front]; } //-------------------------------------------------------------- public boolean isEmpty() // true if queue is empty { return (nItems == 0); } //-------------------------------------------------------------- public boolean isFull() // true if queue is full { return (nItems == maxSize); } //-------------------------------------------------------------- public int size() // number of items in queue { return nItems; } //-------------------------------------------------------------- } // end class Queue //////////////////////////////////////////////////////////////// public class QueueApp { public static void main(String[] args) { Queue theQueue = new Queue(5); // queue holds 5 items theQueue.insert(10); // insert 4 items theQueue.insert(20); theQueue.insert(30); theQueue.insert(40); theQueue.remove(); // remove 3 items theQueue.remove(); // (10, 20, 30) theQueue.remove(); theQueue.insert(50); // insert 4 more items theQueue.insert(60); // (wraps around) theQueue.insert(70); theQueue.insert(80); while (!theQueue.isEmpty()) // remove and display { // all items long n = theQueue.remove(); // (40, 50, 60, 70, 80) System.out.print(n); System.out.print(" "); } System.out.println(""); } // end main() } // end class QueueApp
二叉查找树(BST)
BSTree
package Tree; //http://jiangzhengjun.iteye.com/blog/561590 //二叉查找树的节点类 class BSTreeNode { int data;//数据域 BSTreeNode right;//左孩子 BSTreeNode left;//右孩子 //构造二叉查找树的节点 public BSTreeNode(int data, BSTreeNode right, BSTreeNode left) { this.data = data; this.right = right; this.left = left; } } public class BSTree { BSTreeNode rootNode;// 创建根节点 // 创建二叉查找树 public void createBSTree(int[] A) { rootNode = new BSTreeNode(A[0], null, null);// 初始化根节点 for (int i = 1; i < A.length; i++) {// 逐个取出数组A中的元素用来构造二叉查找树 BSTreeNode tmpNode = rootNode; while (true) { if (tmpNode.data == A[i]) break; if (tmpNode.data > A[i]) {// 小于等于根节点 if (tmpNode.left == null) {// 如果左孩子为空,这把当前数组元素插入到左孩子节点的位置 tmpNode.left = new BSTreeNode(A[i], null, null); break; } tmpNode = tmpNode.left;// 如果不为空的话,则把左孩子节点用来和当前数组元素作比较 } else {// 大于根节点 if (tmpNode.right == null) {// 如果右孩子为空,这把当前数组元素插入到左孩子节点的位置 tmpNode.right = new BSTreeNode(A[i], null, null); break; } tmpNode = tmpNode.right;// 如果不为空的话,则把右孩子节点用来和当前数组元素作比较 } } } } // 中序遍历二叉查找树(中序遍历之后便可以排序成功) public void inOrderBSTree(BSTreeNode x) { if (x != null) { inOrderBSTree(x.left);// 先遍历左子树 System.out.print(x.data + ",");// 打印中间节点 inOrderBSTree(x.right);// 最后遍历右子树 } } // 查询二叉排序树--递归算法 public BSTreeNode searchBSTree1(BSTreeNode x, BSTreeNode k) { if (x == null || k.data == x.data) { return x;// 返回查询到的节点 } if (k.data < x.data) {// 如果k小于当前节点的数据域 return searchBSTree1(x.left, k);// 从左孩子节点继续遍历 } else {// 如果k大于当前节点的数据域 return searchBSTree1(x.right, k);// 从右孩子节点继续遍历 } } // 查询二叉排序树--非递归算法 public BSTreeNode searchBSTree2(BSTreeNode x, BSTreeNode k) { while (x != null && k.data != x.data) { if (x.data > k.data) { x = x.left;// 从左孩子节点继续遍历 } else { x = x.right;// 从右孩子节点继续遍历 } } return x; } // 查找二叉查找树的最小节点 public BSTreeNode searchMinNode(BSTreeNode x) { while (x.left != null) { x = x.left; } return x; } // 查找二叉查找树的最大节点 public BSTreeNode searchMaxNode(BSTreeNode x) { while (x.right != null) { x = x.right; } return x; } // 插入节点进入二叉查找树 public void insert(BSTreeNode k) { BSTreeNode root = rootNode; //System.out.println("\n*****************"); //System.out.println("rootNode=" + rootNode.data); while (true) { if (root.data == k.data) return; else if (root.data > k.data) { if (root.left == null) { root.left = k; break; } root = root.left; } else { if (root.right == null) { root.right = k; break; } root = root.right; } } } // 删除二叉查找树中指定的节点 public void delete(BSTreeNode k) {// 分三种情况删除 if (k.left == null && k.right == null) {// 第一种情况--没有子节点的情况下 //System.out.println("#####没有子节点的情况"); BSTreeNode p = parent(k); //System.out.println("父节点为:"+p.data+" "+p.left.data+" "+p.right.data); if (p.left == k) {// 其为父亲节点的左孩子 p.left = null; } else if (p.right == k) {// 其为父亲节点的右孩子 p.right = null; } } else if (k.left != null && k.right != null) {// 第二种情况--有两个孩子节点的情况下 //System.out.println("\n#####左右子树不为空的情况"); //由直接后继取代删除的节点 BSTreeNode s = successor(k);// k的后继节点 delete(s); k.data = s.data; //只是简单的data替换 //BSTreeNode suc = successor(k); //后继 //BSTreeNode pre = predecessor(k); //前驱 //k.data = pre.data; //BSTreeNode parent = parent(pre); //parent.right = pre.left; //delete(pre); } else {// 第三种情况--只有一个孩子节点的情况下 //System.out.println("#####只有一个孩子节点的情况"); BSTreeNode p = parent(k); if (p.left == k) { if (k.left != null) { p.left = k.left; } else { p.left = k.right; } } else if (p.right == k) { if (k.left != null) { p.right = k.left; } else { p.right = k.right; } } } } // 查找节点的前驱节点 public BSTreeNode predecessor(BSTreeNode k) { if (k.left != null) { return searchMaxNode(k.left);// 左子树的最大值 } BSTreeNode y = parent(k); //System.out.println("K的父节点(k的data为54):" + y.data); while (y != null && k == y.left) {// 向上找到最近的一个节点,其父亲节点的右子树包涵了当前节点或者其父亲节点为空 k = y; y = parent(y); } return y; } // 查找节点的后继节点 public BSTreeNode successor(BSTreeNode k) { if (k.right != null) { return searchMinNode(k.right);// 右子树的最小值 } //为了避免54,87,43的情况 BSTreeNode y = parent(k); //System.out.println("K的父节点(k的data为54):" + y.data); if (y == null) return null; while (y != null) { if (y.left == k) { return y; //为左子树情况,后继为父节点 } else { k = y; //否则递归 y = parent(y); } } return y; } // 求出父亲节点,在定义节点类BSTreeNode的时候,没有申明父亲节点,所以这里专门用parent用来输出父亲节点(主要是不想修改代码了,就在这里加一个parent函数吧) public BSTreeNode parent(BSTreeNode k) { BSTreeNode p = rootNode; BSTreeNode tmp = null; while (p != null && p.data != k.data) {// 最后的p为p.data等于k.data的节点,tmp为p的父亲节点 if (p.data > k.data) { tmp = p;// 临时存放父亲节点 p = p.left; } else { tmp = p;// 临时存放父亲节点 p = p.right; } } return tmp; } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int[] A = { 23, 12, 12, 43, 2, 87, 54 }; BSTreeNode searchNode1 = null;// 递归查找到的结果 BSTreeNode searchNode2 = null;// 非递归查找到的结果 BSTreeNode searchMinNode = null;// 最小节点 BSTreeNode searchMaxNode = null;// 最大节点 BSTreeNode k = null, l = null, p = null, q = null, m = null, n = null;// 申明6个节点k,l,p,q,m,n System.out.print("打印出数组A中的元素"); for (int i = 0; i < A.length; i++) System.out.print(A[i] + ","); BSTree bs = new BSTree(); bs.createBSTree(A);// 创建二叉查找树 System.out.println(); System.out.print("中序遍历构造的二叉查找树:"); bs.inOrderBSTree(bs.rootNode);// 中序遍历二叉查找树 k = new BSTreeNode(23, null, null);// 初始化一节点k,其data为null,左右孩子为null l = new BSTreeNode(17, null, null);// 初始化一节点l,其data为null,左右孩子为null q = new BSTreeNode(12, null, null);// 初始化一节点q,其data为null,左右孩子为null m = bs.searchBSTree2(bs.rootNode, k);// 从二叉查找树里面查找一个节点,其m.data为k.data(这个m节点在后面用来测试程序) searchNode1 = bs.searchBSTree1(bs.rootNode, k);// 查询二叉查找树----递归算法 searchNode2 = bs.searchBSTree2(bs.rootNode, k);// 查询二叉查找树----递归算法 System.out.println(""); System.out.println("递归算法--查找节点域:" + searchNode1.data + "左孩子:" + searchNode1.left.data + " 右孩子:" + searchNode1.right.data);// 这里的左孩子或者右孩子节点可能打印为空,会出现null异常 //System.out.println("非递归算法--查找节点域:" + searchNode2.data + "左孩子:" //+ searchNode2.left.data + " 右孩子:" + searchNode2.right.data);// 这里的左孩子或者右孩子节点可能打印为空,会出现null异常 searchMinNode = bs.searchMinNode(bs.rootNode);// 找到最小节点 searchMaxNode = bs.searchMaxNode(bs.rootNode);// 找到最大节点 System.out.println("最小节点:" + searchMinNode.data); System.out.println("最大节点:" + searchMaxNode.data); bs.insert(l);// 把l节点插入到二叉查找树中 System.out.println("插入l节点(l的data为17)之后的二叉查找树的中序遍历结果:"); bs.inOrderBSTree(bs.rootNode);// 中序遍历二叉查找树 p = bs.parent(bs.searchBSTree2(bs.rootNode, q));// 取q节点的父亲节点 System.out.println("\nq的父亲节点(q的data为12):" + p.data + " 左孩子:" + p.left.data + " 右孩子:" + p.right.data);// 这里的左孩子或者右孩子节点可能打印为空,会出现null异常 //bs.delete(l); //删除17 //System.out.print("删除l节点(l的data为17)之后的二叉查找树的中序遍历结果:"); //bs.inOrderBSTree(bs.rootNode);// 中序遍历二叉查找树 bs.insert(new BSTreeNode(15, null, null));// 把l节点插入到二叉查找树中 System.out.print("\n插入节点15之后的二叉查找树的中序遍历结果:"); bs.inOrderBSTree(bs.rootNode); bs.delete(bs.searchBSTree2(bs.rootNode, q)); //删除12 System.out.print("\n删除节点12之后的二叉查找树的中序遍历结果:"); bs.inOrderBSTree(bs.rootNode); m = bs.searchBSTree2(bs.rootNode, k); System.out.println("\nm节点(m的data为23):" + m.data + " 左孩子:" + m.left.data + " 右孩子:" + m.right.data); BSTreeNode node = bs.searchBSTree1(bs.rootNode, new BSTreeNode(2, null, null)); System.out.println("\ndata:" + node.data); n = bs.predecessor(node); if (n == null) System.out.println("K的前驱节点为:null"); else System.out.println("K的前驱节点(k的data为" + node.data + "):" + n.data); n = bs.successor(node); if (n == null) System.out.println("K的后继节点为:null"); else System.out.println("K的前驱节点(k的data为" + node.data + "):" + n.data); } }
双向链表(doubly linked list)
View Code
class Node<T> { T value; Node<T> prev = null; Node<T> next = null; public boolean equals(Node<T> node) { if (value.equals(node.value)) { return true; } return false; } public int hashCode() { return value.hashCode(); } public String toString() { if (value == null) return "-1"; return value.toString(); } } class DoubleLinkedList<T> { private Node<T> head; // 头节点 private Node<T> tail; private int len; // 链表大小 //初始化LinkedList public DoubleLinkedList() { /*head = new Node<T>(); tail = new Node<T>(); head.next = tail; head.prev = null; tail.next = null; tail.prev = head; len = 0;*/ } public void init() { head = new Node<T>(); tail = new Node<T>(); head.next = tail; head.prev = null; tail.next = null; tail.prev = head; len = 0; } public void destroyList() { } public void clearList() { init(); } // 判断链表是否为空 public boolean isEmpty() { if (tail == head.next || head == tail.prev) { return true; } return false; } // 链表的遍历(从head顺序遍历) public void traversalFromHead() { if (isEmpty()) { System.out.println("The Doubly Linked List is empty"); } else { /*Node<T> node = head.next; while (null != node.next) { System.out.print(node + "-->"); node = node.next; }*/ Node<T> node = head; len = 0; while (tail != node.next) { System.out.print(node.next + "-->"); len++; node = node.next; } System.out.println(); } } // 链表的遍历(从tail倒序遍历) public void traversalFromTail() { if (isEmpty()) { System.out.println("The Doubly Linked List is empty"); } else { Node<T> node = tail.prev; while (null != node.prev) { System.out.print(node + "-->"); node = node.prev; } System.out.println(); } } public int getLength() { return len; } // 添加节点到链表的头部 public void addToHead(Node<T> node) { /*if (tail == head.next) { head.next = node; tail.prev = node; } else { node.next = head.next; node.prev = head; head.next.prev = node; head.next = node; }*/ // 修改node节点的前驱和后继 node.next = head.next; node.prev = head; // 修改node前驱节点的后继及后继节点的前驱 head.next.prev = node; head.next = node; } // 添加节点到链表的尾部 public void addToTail(Node<T> node) { /*if (tail.prev == head) { tail.prev = node; head.next = node; } else { node.prev = tail.prev; node.next = tail; tail.prev.next = node; tail.prev = node; }*/ // 修改node节点的前驱和后继 node.prev = tail.prev; node.next = tail; // 修改node前驱节点的后继及后继节点的前驱 tail.prev.next = node; tail.prev = node; } // 添加某个值到指定的数值的节点前面 public void insertBefore(Node<T> node, T key) { if (null == head.next || null == tail.prev) { System.out.println("The Doubly Linked List is empty"); } else { Node<T> theNode = head.next; while (null != theNode.next) { if (theNode.next.value.equals(key)) { node.next = theNode.next; theNode.next.prev = node; theNode.next = node; node.prev = theNode; break; } theNode = theNode.next; } } } // 添加某个值到指定的数值的节点后面 public void insertAfter(Node<T> node, T key) { if (null == head.next || null == tail.prev) { System.out.println("The Doubly Linked List is empty"); } else { Node<T> theNode = head; while (tail != theNode.next) { if (theNode.next.value.equals(key)) { node.next = theNode.next.next; theNode.next.next.prev = node; theNode.next.next = node; node.prev = theNode.next; break; } theNode = theNode.next; } } } //删除第一个元素 public void deleteFirst() { if (isEmpty()) { return; } else { head.next = head.next.next;//修改后继 head.next.next.prev = head;//修改前驱 } } //删除最后一个元素 public void deleteLast() { if (!isEmpty()) { //顺序不能错 tail.prev.prev.next = tail;//修改后继 tail.prev = tail.prev.prev;//修改前驱 } } //判断指定的节点是否存在 public boolean existsNode(Node<T> node) { boolean result = false; Node<T> tmp = head; while (tail != tmp.next) { if (!node.value.equals(tmp.next.value)) { result = false; } else { result = true; return result; } tmp = tmp.next; } return result; } //搜索指定位置的节点 public Node<T> searchNode(int pos) { if (isEmpty()) { System.out.println("The Doubly Linked List is empty"); } else { Node<T> node = head; int count = 0; if (pos >= len) { return null; } else { while (tail != node.next) { if (count == pos) { return node.next; } count++; node = node.next; } System.out.println(); } } return null; } //删除指定的node public void deleteNode(Node<T> node) { Node<T> tmp = head; if (existsNode(node)) { System.out.println("删除节点的值为:" + node.value); while (tail != tmp.next) { if (node.value.equals(tmp.next.value)) { System.out.println("删除节点的前驱节点的值为:" + tmp.value); tmp.next = tmp.next.next;//修改后继 tmp.next.next.prev = tmp;//修改前驱 } tmp = tmp.next; } } } //删除指定位置的node public void deleteNode(int pos) { Node<T> node = searchNode(pos); System.out.println("位置从0开始,pos="+pos+"位置对应的节点值为:"+node.value); deleteNode(node); } //获取双向链表中第一个元素:不包括头指针 public Node<T> getFirstNode() { return searchNode(0); } //获取双向链表最后一个元素:不包括尾指针 public Node<T> getLastNode() { return searchNode(len-1); } } public class DoubleLinkedListTest { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub DoubleLinkedList<Integer> doublyLinkedList = new DoubleLinkedList<Integer>(); /************************ * 初始化操作 * **********************/ doublyLinkedList.init(); System.out.println("########################################"); System.out.println("新建双向链表:***"); doublyLinkedList.traversalFromHead(); for (int i = 0; i < 2; i++) { Node<Integer> node = new Node<Integer>(); node.value = i; doublyLinkedList.addToHead(node); } System.out.println("########################################"); System.out.println("初始化双向链表:***"); doublyLinkedList.traversalFromHead(); for (int i = 10; i < 16; i++) { Node<Integer> node = new Node<Integer>(); node.value = i; doublyLinkedList.addToHead(node); } /************************ * 插入操作 * **********************/ Node<Integer> node = new Node<Integer>(); node.value = 88; doublyLinkedList.insertAfter(node, 11); node = new Node<Integer>(); node.value = 24; doublyLinkedList.insertBefore(node, 11); node = new Node<Integer>(); node.value = 100; doublyLinkedList.addToTail(node); System.out.println("########################################"); System.out.println("双向链表插入操作:***"); doublyLinkedList.traversalFromHead(); System.out.println("双向链表长度为:" + doublyLinkedList.getLength()); /************************ * 删除操作 * **********************/ //删除当前双向链表中第一个节点 doublyLinkedList.deleteFirst(); //删除当前双向链表中最后节点 doublyLinkedList.deleteLast(); //删除当前双向链表中存在的节点 node = new Node<Integer>(); node.value = 11; doublyLinkedList.deleteNode(node); //删除不存在的节点 node = new Node<Integer>(); node.value = 1000; doublyLinkedList.deleteNode(node); System.out.println("########################################"); System.out.println("双向链表删除操作:***"); doublyLinkedList.traversalFromHead(); System.out.println("双向链表长度为:" + doublyLinkedList.getLength()); //删除指定位置的节点 doublyLinkedList.deleteNode(1); System.out.println("双向链表删除操作:***"); doublyLinkedList.traversalFromHead(); System.out.println("双向链表长度为:" + doublyLinkedList.getLength()); /************************ * 清空列表操作 * **********************/ doublyLinkedList.clearList(); System.out.println("########################################"); System.out.println("双向链表清空操作:***"); doublyLinkedList.traversalFromHead(); } }