算法与数据结构 - 链表常见操作

链表常见操作

              最近在复习算法与数据结构, 一边写写博客啦.

快指针和慢指针

public class Main {
    public static void main(String[] args) {
        printFastAndSlow(ListNode.createLinkedList(new int[]{1, 2, 3, 4, 5, 6, 7}));
    }

    private static void printFastAndSlow(ListNode head) {
        ListNode fast = head;
        ListNode slow = head;
        while (fast != null && fast.next != null && slow != null) {
            fast = fast.next.next;
            slow = slow.next;
        }
        System.out.println("fast: " + (fast == null? "null":fast.val));
        System.out.println("slow: " + (slow == null? "null":fast.val));
    }
}

特性一:

快指针比慢指针来得快, 如果出现了环路, 可以迅速判断出来. 见leetcode题目: