【Java--数据结构】链表经典OJ题详解

以下是针对题目中给出的两个经典链表操作的Java代码示例：

1. 反转单向链表

class ListNode {
    int val;
    ListNode next;
 
    ListNode(int x) {
        val = x;
        next = null;
    }
}
 
public class ReverseLinkedList {
    public ListNode reverseList(ListNode head) {
        ListNode prev = null;
        ListNode curr = head;
        while (curr != null) {
            ListNode nextTemp = curr.next;
            curr.next = prev;
            prev = curr;
            curr = nextTemp;
        }
        return prev;
    }
}

2. 判断链表是否有环

class ListNode {
    int val;
    ListNode next;
 
    ListNode(int x) {
        val = x;
        next = null;
    }
}
 
public class LinkedListCycle {
    public boolean hasCycle(ListNode head) {
        ListNode slow = head;
        ListNode fast = head;
        while (fast != null && fast.next != null) {
            slow = slow.next;
            fast = fast.next.next;
            if (slow == fast) {
                return true;
            }
        }
        return false;
    }
}

这两个示例分别展示了如何反转单向链表和如何检测链表是否有环。这些操作在链表的实际应用中非常常见，并且是链表操作面试题的基础。