loop = k + m 分析起始点的位置:通过慢指针继续走loop - m步就可以到达环的起始位置,正好k=loop - m,所以,相遇时把快指针指向头指针,两个指针以相同的速度走k步就可以一起到达环的起始位置了。 可以看看这篇文章的解释,看着像我邮学长的blog 3 代码 publicListNodedetectCycle(ListNode head){ListNodefast=...
不加虚拟头节点 /*** Definition for singly-linked list.* public class ListNode {* int val;*...
/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: //数学题 + 快慢指针 //fast 2 step 每次 . slow 1 step 每次 //用 do whlie 可以避免边界 ListNode *detec...
Output: no cycle Explanation: There is no cycle in the linked list. Follow up: Can you solve it without using extra space? 空间复杂度O(n) 1 2 3 4 5 6 7 8 9 10 11 12 13 publicListNode detectCycle(ListNode head) {//链表 my Set<ListNode> nodeSet =newHashSet<ListNode>(); while(...
1559.Detect-Cycles-in-2D-Grid (M) 1568.Minimum-Number-of-Days-to-Disconnect-Island (H-) 1617.Count-Subtrees-With-Max-Distance-Between-Cities (H-) 1654.Minimum-Jumps-to-Reach-Home (H-) 1905.Count-Sub-Islands (M+) 2045.Second-Minimum-Time-to-Reach-Destination (M+) 2101.Detonate-the-...
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双指针主要用来遍历数组,两个指针指向不同的元素,从而协同完成任务。我们也可以类比这个概念,推广到多个数组的多个指针。 若两个指针指向同一数组,遍历方向相同且不会相交,可以称之为滑动窗口(两个指针包围的区域为当前的窗口),经常用于区间搜索。 若两个指针指向同一数组,但是遍历方向相反,那我们可以用来进行搜索,这时...
LeetCode 刷题随手记 - 第一部分 前 256 题(非会员),仅算法题,的吐槽 https://leetcode.com/problemset/algorithms/...