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2095. Delete the Middle Node of a Linked List

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leetcode-scala/src/main/scala/LeetCode75/Linked_List
- 2095. Delete the Middle Node of a Linked List.sc

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	`1`	`+`
	`2`	`+`
	`3`	`+/**`
	`4`	`+ * Definition for singly-linked list.`
	`5`	`+ */`
	`6`	`+`
	`7`	`+class ListNode(_x: Int = 0, _next: ListNode = null) {`
	`8`	`+ var next: ListNode = _next`
	`9`	`+ var x: Int = _x`
	`10`	`+}`
	`11`	`+`
	`12`	`+object Solution {`
	`13`	`+ import scala.annotation.tailrec`
	`14`	`+`
	`15`	`+ def len(head: ListNode): Int = {`
	`16`	`+ @tailrec def go(node: ListNode, acc: Int): Int = {`
	`17`	`+ if (node.next == null) acc + 1`
	`18`	`+ else go(node.next, acc + 1)`
	`19`	`+ }`
	`20`	`+ go(head, 0)`
	`21`	`+ }`
	`22`	`+`
	`23`	`+ def deleteMiddle(head: ListNode): ListNode = {`
	`24`	`+ val llen = len(head)`
	`25`	`+ @tailrec def go(node: ListNode, curPos: Int): Unit = {`
	`26`	`+ if (curPos == llen / 2 - 1) {`
	`27`	`+ node.next = node.next.next`
	`28`	`+ } else go(node.next, curPos + 1)`
	`29`	`+ }`
	`30`	`+ if (head.next == null) null`
	`31`	`+ else {`
	`32`	`+ go(head, 0)`
	`33`	`+ head`
	`34`	`+ }`
	`35`	`+ }`
	`36`	`+`
	`37`	`+ def pprint(head: ListNode): Unit = {`
	`38`	`+ @tailrec def go(node: ListNode, i: Int): Unit = {`
	`39`	`+ print(s"[$i]=${node.x}, ")`
	`40`	`+ if (node.next == null) ()`
	`41`	`+ else go(node.next, i + 1)`
	`42`	`+ }`
	`43`	`+`
	`44`	`+ go(head, 0)`
	`45`	`+ }`
	`46`	`+}`
	`47`	`+`
	`48`	`+val list = ListNode(1)`
	`49`	`+Solution.len(list)`
	`50`	`+`
	`51`	`+Solution.pprint(list)`
	`52`	`+val nl = Solution.deleteMiddle(list)`
	`53`	`+Solution.pprint(nl)`

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