本文為大家分享了java實現(xiàn)鏈表反轉(zhuǎn)的具體代碼，供大家參考，具體內(nèi)容如下

算法題：實現(xiàn)鏈表的反轉(zhuǎn)

提供了2種方法，迭代法、遞歸法。

（為了方便輸出可視化，在自定義的ListNode中重寫了toString方法。）

/** * Created By --- on 2021/8/12 * 以下代碼可以直接粘貼進編譯器輸出 */public class ReverseList { public static void main(String[] args) { ListNode head = new ListNode(3, new ListNode(5, new ListNode(8, new ListNode(9)))); System.out.println('初始鏈表：' + head); ListNode newList = reverseList(head); System.out.println('使用迭代法反轉(zhuǎn)鏈表：' + newList); ListNode newList2 = reverseList2(null, newList); System.out.println('使用遞歸法反轉(zhuǎn)鏈表：' + newList2); } /** * 迭代法 */ public static ListNode reverseList(ListNode head) { ListNode pre = null; ListNode cur = head; ListNode tmp; while (cur != null) { tmp = cur.next; cur.next = pre; pre = cur; cur = tmp; } return pre; } /** * 遞歸法 */ public static ListNode reverseList2(ListNode pre, ListNode cur) { if (cur == null) { return pre; } ListNode tmp = cur.next; cur.next = pre; pre = cur; cur = tmp; return reverseList2(pre, cur); } } /** * singly-linked list */class ListNode { int val; ListNode next; ListNode() { } ListNode(int val) { this.val = val; } ListNode(int val, ListNode next) { this.val = val; this.next = next; } @Override public String toString() { StringBuilder sb = new StringBuilder(String.valueOf(val)); ListNode next = this.next; while (next != null) { sb.append(next.val); next = next.next; } return sb.toString(); }}

輸出結果：

再為大家分享一段java實現(xiàn)鏈表反轉(zhuǎn)的三種方式

分別通過棧、遞歸、指針的方式實現(xiàn)：

import java.util.Stack; public class ReverseLinkedList { public static void main(String[] args) {ReverseLinkedList reverseLinkedList = new ReverseLinkedList();reverseLinkedList.test(); } public void test() {Node node1 = new Node(1);Node node2 = new Node(2);Node node3 = new Node(3);node1.setNext(node2);node2.setNext(node3);//方法需要替換node1 = reverseByPointer(node1);while (node1 != null) { System.out.println(node1.val); node1 = node1.getNext();} } //棧實現(xiàn) private Node reverseByStack(Node head) {if (head == null || head.getNext() == null) { return head;}Stack<Node> stack = new Stack<>();while (head != null) { stack.push(head); head = head.getNext();}head = stack.pop();Node tmp = head;while (!stack.empty()) { Node node = stack.pop(); node.setNext(null); tmp.setNext(node); tmp = node;}return head; } //遞歸實現(xiàn) private Node reverseByRecursion(Node head) {if (head == null || head.getNext() == null) { return head;}//遞歸獲取當前節(jié)點的后一個節(jié)點Node tmp = reverseByRecursion(head.getNext());Node node = head.getNext();head.setNext(null);node.setNext(head);return tmp; } //指針實現(xiàn) private Node reverseByPointer(Node head) {if (head == null || head.getNext() == null) { return head;}//pre指針指向前一個節(jié)點，初始第一個節(jié)點的前節(jié)點為空Node pre = null;//tmp指針指向當前節(jié)點Node tmp = null;while (head != null) { //tmp指針指向head頭指針節(jié)點 tmp = head; //head頭指針向后遍歷 head = head.getNext(); //反轉(zhuǎn)，設置當前節(jié)點的下一個節(jié)點為前一個節(jié)點 tmp.setNext(pre); //pre指針向后移動，指向當前節(jié)點 pre = tmp;}return tmp; } private class Node {private int val; private Node next; public Node(int val) { this.val = val;} public Node getNext() { return next;} public void setNext(Node next) { this.next = next;} }}

以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持好吧啦網(wǎng)。