May 30, 2022 · May 11, 2022 · May 11, 2022 · May 11, 2022 · May 12, 2022 · May 12, 2022
diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1154,7 +1154,75 @@ class MyLinkedList {
		}
		```

	Scala:
	```scala
	class ListNode(_x: Int = 0, _next: ListNode = null) {
	var next: ListNode = _next
	var x: Int = _x
	}

	class MyLinkedList() {

	var size = 0 // 链表尺寸
	var dummy: ListNode = new ListNode(0) // 虚拟头节点

	// 获取第index个节点的值
	def get(index: Int): Int = {
	if (index < 0 \|\| index >= size) {
	return -1;
	}
	var cur = dummy
	for (i <- 0 to index) {
	cur = cur.next
	}
	cur.x // 返回cur的值
	}

	// 在链表最前面插入一个节点
	def addAtHead(`val`: Int) {
	addAtIndex(0, `val`)
	}

	// 在链表最后面插入一个节点
	def addAtTail(`val`: Int) {
	addAtIndex(size, `val`)
	}

	// 在第index个节点之前插入一个新节点
	// 如果index等于链表长度,则说明新插入的节点是尾巴
	// 如果index等于0,则说明新插入的节点是头
	// 如果index>链表长度,则说明为空
	def addAtIndex(index: Int, `val`: Int) {
	if (index > size) {
	return
	}
	var loc = index // 因为参数index是val不可变类型,所以需要赋值给一个可变类型
	if (index < 0) {
	loc = 0
	}
	size += 1 //链表尺寸+1
	var pre = dummy
	for (i <- 0 until loc) {
	pre = pre.next
	}
	val node: ListNode = new ListNode(`val`, pre.next)
	pre.next = node
	}
	// 删除第index个节点
	def deleteAtIndex(index: Int) {
	if (index < 0 \|\| index >= size) {
	return
	}
	size -= 1
	var pre = dummy
	for (i <- 0 until index) {
	pre = pre.next
	}
	pre.next = pre.next.next
	}

	}
	```


		-----------------------
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