Commit 1ae42b2

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update q206

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+16

-26

lines changed

+16

-26

lines changed

Lines changed: 8 additions & 17 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,28 +1,19 @@`
`1`	`1`	`package 链表操作.q206_反转链表.f1;`
`2`	`2`
`3`		`-import java.util.ArrayList;`
`4`		`-import java.util.List;`
`5`		`-`
`6`	`3`	`/**`
`7`		`- * 暴力法舍弃空间 o(n)`
	`4`	`+ * 遍历直接反向修改next指针 o(n)`
`8`	`5`	`*/`
`9`	`6`	`class Solution {`
	`7`	`+`
`10`	`8`	`public ListNode reverseList(ListNode head) {`
`11`		`- if (head == null \|\| head.next == null) {`
`12`		`- return head;`
`13`		`- }`
`14`		`- List<Integer> list = new ArrayList<>();`
	`9`	`+ ListNode pre = null;`
`15`	`10`	`ListNode temp = head;`
`16`	`11`	`while (temp != null) {`
`17`		`- list.add(temp.val);`
`18`		`- temp = temp.next;`
`19`		`- }`
`20`		`- ListNode rs = new ListNode(list.get(list.size() - 1));`
`21`		`- ListNode t1 = rs;`
`22`		`- for (int i = list.size() - 2; i >= 0; i--) {`
`23`		`- t1.next = new ListNode(list.get(i));`
`24`		`- t1 = t1.next;`
	`12`	`+ ListNode t = temp.next;`
	`13`	`+ temp.next = pre;`
	`14`	`+ pre = temp;`
	`15`	`+ temp = t;`
`25`	`16`	`}`
`26`		`- return rs;`
	`17`	`+ return pre;`
`27`	`18`	`}`
`28`	`19`	`}`

Lines changed: 8 additions & 9 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,18 +1,17 @@`
`1`	`1`	`package 链表操作.q206_反转链表.f2;`
`2`	`2`
`3`	`3`	`/**`
`4`		`- * 遍历直接反向修改next指针 o(n)`
	`4`	`+ * 递归法 o(n)`
`5`	`5`	`*/`
`6`	`6`	`class Solution {`
	`7`	`+`
`7`	`8`	`public ListNode reverseList(ListNode head) {`
`8`		`- ListNode pre = null;`
`9`		`- ListNode temp = head;`
`10`		`- while (temp != null) {`
`11`		`- ListNode t = temp.next;`
`12`		`- temp.next = pre;`
`13`		`- pre = temp;`
`14`		`- temp = t;`
	`9`	`+ if (head == null \|\| head.next == null) {`
	`10`	`+ return head;`
`15`	`11`	`}`
`16`		`- return pre;`
	`12`	`+ ListNode p = reverseList(head.next);`
	`13`	`+ head.next.next = head;`
	`14`	`+ head.next = null;`
	`15`	`+ return p;`
`17`	`16`	`}`
`18`	`17`	`}`

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