我有以下用于反转链接列表的代码:
node old = head;
head = null;
while (old!=null) {
node temp = old.link;
old.link = head;
head = old;
old = temp;
}
有人可以解释一下这段代码的每一行吗，因为我试图通过绘制框图来了解如何反转列表，但我仍然不明白。
最佳答案
假设 head 是指向列表头的指针 (1, 2, 3, 4):
+-----+ link +-----+ link +-----+ link +-----+ link
| 1 | ---> | 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ +-----+ +-----+ +-----+
^ head
旧节点 = 头；
头=空；
+-----+ link +-----+ link +-----+ link +-----+ link
| 1 | ---> | 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ +-----+ +-----+ +-----+
^ old
null
^ head
(while 循环的第一次迭代...)
节点温度 = old.link;
+-----+ link +-----+ link +-----+ link +-----+ link
| 1 | ---> | 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ +-----+ +-----+ +-----+
^ old ^ temp
null
^ head
old.link = head;
+-----+ link +-----+ link +-----+ link +-----+ link
| 1 | -+ | 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ | +-----+ +-----+ +-----+
^ old | ^ temp
|
+----------------------------------------> null
^ head
头=旧；
+-----+ link +-----+ link +-----+ link +-----+ link
| 1 | -+ | 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ | +-----+ +-----+ +-----+
^ old | ^ temp
^ head |
+----------------------------------------> null
旧=临时；
+-----+ link +-----+ link +-----+ link
| 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ +-----+ +-----+
^ old
^ temp +-----+
| 1 | ---> null
+-----+
^ head
(第二次迭代...)
节点温度 = old.link;
+-----+ link +-----+ link +-----+ link
| 2 | ---> | 3 | ---> | 4 | ---> null
+-----+ +-----+ +-----+
^ old ^ temp
+-----+ link
| 1 | ---> null
+-----+
^ head
old.link = head;
+-----+ link +-----+ link +-----+ link
| 2 | -+ | 3 | ---> | 4 | ---> null
+-----+ | +-----+ +-----+
^ old | ^ temp
| +-----+ link
+--------------> | 1 | ---> null
+-----+
^ head
头=旧；
+-----+ link +-----+ link +-----+ link
| 2 | -+ | 3 | ---> | 4 | ---> null
+-----+ | +-----+ +-----+
^ old | ^ temp
^ head | +-----+ link
+--------------> | 1 | ---> null
+-----+
旧=临时；
+-----+ link +-----+ link
| 3 | ---> | 4 | ---> null
+-----+ +-----+
^ old
^ temp
+-----+ link +-----+ link
| 2 | ---> | 1 | ---> null
+-----+ +-----+
^ head
重复直到old指向末尾的null(即，直到原始列表为空)。
关于java - 了解如何反转链表？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19669843/