单链表及单链表翻转

src/leo/class02/LinkedList.java

@@ -0,0 +1,206 @@
+package leo.class02;
+
+import java.lang.reflect.Array;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author Leo
+ * @ClassName LinkedList
+ * @DATE 2020/11/18 3:24 下午
+ * @Description 链表练习
+ * 单向链表
+ * 双向链表
+ * 链表翻转
+ *
+ */
+public class LinkedList {
+
+    public static class Node{
+        int value;
+        Node next;
+
+
+        public Node(int value) {
+            this.value = value;
+        }
+    }
+
+    public class DoubleNode{
+        int value;
+        DoubleNode pre;
+        DoubleNode next;
+        public DoubleNode(int value) {
+            this.value = value;
+        }
+    }
+
+    /**
+     * 功能描述 : 单链表翻转
+     * @author Leo
+     * @date 2020/11/18 3:42 下午
+     * @param head
+     * @return leo.class02.LinkedList.Node
+     */
+    public static Node reverseNode(Node head) {
+
+        Node pre = null;
+        Node next = null;
+        while (head != null) {
+            next = head.next;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+    }
+
+    public static Node reverseNode1(Node head) {
+        Node pre = null;
+        Node next = null;
+
+        while (head != null) {
+            next = head;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+    }
+
+    public static Node reverseNode2(Node head) {
+        Node pre = null;
+        Node next = null;
+        while (head != null) {
+            next = head;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+    }
+
+    public static Node reverseNode3(Node head) {
+        Node pre = null;
+        Node next = null;
+        while (head != null) {
+            next = head.next;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+
+    }
+
+    public static Node reverseNode4(Node head) {
+        Node pre = null;
+        Node next = null;
+        while (head != null) {
+            next = head.next;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+    }
+
+
+    public static DoubleNode reverseDoubleNode(DoubleNode head) {
+        DoubleNode pre = null;
+        DoubleNode next;
+        while (head != null) {
+            next = head.next;
+            head.pre = next;
+            head.next = pre;
+            pre = head;
+            head = next;
+        }
+        return pre;
+    }
+
+
+    /**
+     * 功能描述 : 随机生成单链表
+     * @author Leo
+     * @date 2020/11/18 6:43 下午
+     * @param sizeMax
+     * @param range
+     * @return leo.class02.LinkedList.Node
+     */
+    public static Node randomNode(int sizeMax, int range) {
+        int size = (int) ((sizeMax + 1) * Math.random());
+        if (size == 0) {
+            return null;
+        }
+        Node head = new Node(randomInt(range));
+        Node pre = head;
+        size--;
+        while (size != 0) {
+            Node cur = new Node(randomInt(range));
+            pre.next = cur;
+            pre = cur;
+            size--;
+        }
+        return head;
+
+    }
+
+    public static int randomInt(int range) {
+        return (int) (Math.random() * (range + 1));
+    }
+
+    /**
+     * 功能描述 : 验证单链表
+     * @author Leo
+     * @date 2020/11/18 9:40 下午
+     * @param nodeList
+     * @param node
+     * @return boolean
+     */
+    public static boolean verifyReverseListAndNode(List<Node> nodeList, Node node) {
+        Node cur = node;
+        for (int i = nodeList.size() - 1; i >= 0; i--) {
+            if (cur==null||cur != nodeList.get(i)) {
+                return false;
+            }
+            cur = cur.next;
+        }
+        return true;
+    }
+
+    /**
+     * 功能描述 : node转list
+     * @author Leo
+     * @date 2020/11/18 10:11 下午
+     * @param node
+     * @return java.util.List<leo.class02.LinkedList.Node>
+     */
+    public static List<Node> nodeToList(Node node) {
+        List<Node> list = new ArrayList<>();
+        Node cur = node;
+        while (cur != null) {
+            list.add(cur);
+            cur = cur.next;
+        }
+        return list;
+    }
+
+    public static void main(String[] args){
+        int maxSize = 40;
+        int range = 90;
+        int testTime = 1000;
+        System.out.println("测试开始");
+        for (int i = 0; i < testTime; i++) {
+            Node head = randomNode(maxSize, range);
+            List<Node> nodeList = nodeToList(head);
+            Node node = reverseNode4(head);
+            if (!verifyReverseListAndNode(nodeList, node)) {
+                System.out.println("nodeFuck!!");
+                break;
+            }
+        }
+        System.out.println("测试结束");
+    }
+
+}