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feat: add swift implementation to lcof2 problem: No.057 (doocs#3100)
 --------- Co-authored-by: Libin YANG <[email protected]>
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‎lcof2/剑指 Offer II 057. 值和下标之差都在给定的范围内/README.md

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Original file line numberDiff line numberDiff line change
@@ -809,6 +809,180 @@ class TreeMultiSet<T = number> {
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}
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```
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#### Swift
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```swift
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class Solution {
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func containsNearbyAlmostDuplicate(_ nums: [Int], _ k: Int, _ t: Int) -> Bool {
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guard nums.count > 1, k > 0, t >= 0 else { return false }
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var ts = TreeSet<Int64>()
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for i in 0..<nums.count {
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let num = Int64(nums[i])
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if let x = ts.ceiling(num - Int64(t)), abs(x - num) <= Int64(t) {
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return true
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}
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ts.insert(num)
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if i >= k {
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ts.remove(Int64(nums[i - k]))
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}
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}
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return false
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}
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}
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class AVLTreeNode<T: Comparable> {
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var value: T
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var height: Int
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var left: AVLTreeNode?
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var right: AVLTreeNode?
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init(value: T) {
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self.value = value
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self.height = 1
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}
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}
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class TreeSet<T: Comparable> {
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private var root: AVLTreeNode<T>?
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func insert(_ value: T) {
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root = insert(root, value)
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}
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func remove(_ value: T) {
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root = remove(root, value)
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}
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func ceiling(_ value: T) -> T? {
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return ceiling(root, value)
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}
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private func insert(_ node: AVLTreeNode<T>?, _ value: T) -> AVLTreeNode<T> {
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guard let node = node else {
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return AVLTreeNode(value: value)
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}
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if value < node.value {
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node.left = insert(node.left, value)
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} else if value > node.value {
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node.right = insert(node.right, value)
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} else {
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return node
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}
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return balance(node)
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}
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private func remove(_ node: AVLTreeNode<T>?, _ value: T) -> AVLTreeNode<T>? {
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guard let node = node else {
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return nil
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}
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if value < node.value {
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node.left = remove(node.left, value)
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} else if value > node.value {
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node.right = remove(node.right, value)
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} else {
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if node.left == nil {
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return node.right
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} else if node.right == nil {
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return node.left
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} else {
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if let minLargerNode = minNode(node.right) {
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node.value = minLargerNode.value
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node.right = remove(node.right, minLargerNode.value)
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}
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}
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}
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return balance(node)
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}
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private func ceiling(_ node: AVLTreeNode<T>?, _ value: T) -> T? {
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guard let node = node else {
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return nil
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}
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if node.value == value {
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return node.value
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} else if node.value < value {
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return ceiling(node.right, value)
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} else {
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return ceiling(node.left, value) ?? node.value
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}
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}
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private func height(_ node: AVLTreeNode<T>?) -> Int {
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return node?.height ?? 0
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}
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private func balanceFactor(_ node: AVLTreeNode<T>) -> Int {
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return height(node.left) - height(node.right)
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}
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private func updateHeight(_ node: AVLTreeNode<T>) {
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node.height = 1 + max(height(node.left), height(node.right))
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}
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private func rotateRight(_ y: AVLTreeNode<T>) -> AVLTreeNode<T> {
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let x = y.left!
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let T2 = x.right
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x.right = y
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y.left = T2
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updateHeight(y)
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updateHeight(x)
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return x
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}
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private func rotateLeft(_ x: AVLTreeNode<T>) -> AVLTreeNode<T> {
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let y = x.right!
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let T2 = y.left
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y.left = x
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x.right = T2
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updateHeight(x)
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updateHeight(y)
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return y
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}
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private func balance(_ node: AVLTreeNode<T>) -> AVLTreeNode<T> {
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updateHeight(node)
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let balance = balanceFactor(node)
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if balance > 1 {
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if balanceFactor(node.left!) < 0 {
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node.left = rotateLeft(node.left!)
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}
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return rotateRight(node)
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}
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if balance < -1 {
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if balanceFactor(node.right!) > 0 {
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node.right = rotateRight(node.right!)
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}
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return rotateLeft(node)
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}
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return node
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}
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private func minNode(_ node: AVLTreeNode<T>?) -> AVLTreeNode<T>? {
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var current = node
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while current?.left != nil {
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current = current?.left
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}
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return current
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}
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}
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```
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<!-- tabs:end -->
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<!-- solution:end -->

‎lcof2/剑指 Offer II 057. 值和下标之差都在给定的范围内/Solution.swift

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class Solution {
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func containsNearbyAlmostDuplicate(_ nums: [Int], _ k: Int, _ t: Int) -> Bool {
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guard nums.count > 1, k > 0, t >= 0 else { return false }
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var ts = TreeSet<Int64>()
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for i in 0..<nums.count {
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let num = Int64(nums[i])
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if let x = ts.ceiling(num - Int64(t)), abs(x - num) <= Int64(t) {
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return true
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}
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ts.insert(num)
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if i >= k {
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ts.remove(Int64(nums[i - k]))
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}
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}
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return false
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}
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}
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class AVLTreeNode<T: Comparable> {
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var value: T
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var height: Int
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var left: AVLTreeNode?
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var right: AVLTreeNode?
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init(value: T) {
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self.value = value
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self.height = 1
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}
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}
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class TreeSet<T: Comparable> {
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private var root: AVLTreeNode<T>?
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func insert(_ value: T) {
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root = insert(root, value)
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}
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func remove(_ value: T) {
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root = remove(root, value)
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}
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func ceiling(_ value: T) -> T? {
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return ceiling(root, value)
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}
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private func insert(_ node: AVLTreeNode<T>?, _ value: T) -> AVLTreeNode<T> {
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guard let node = node else {
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return AVLTreeNode(value: value)
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}
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if value < node.value {
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node.left = insert(node.left, value)
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} else if value > node.value {
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node.right = insert(node.right, value)
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} else {
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return node
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}
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return balance(node)
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}
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private func remove(_ node: AVLTreeNode<T>?, _ value: T) -> AVLTreeNode<T>? {
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guard let node = node else {
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return nil
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}
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if value < node.value {
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node.left = remove(node.left, value)
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} else if value > node.value {
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node.right = remove(node.right, value)
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} else {
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if node.left == nil {
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return node.right
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} else if node.right == nil {
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return node.left
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} else {
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if let minLargerNode = minNode(node.right) {
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node.value = minLargerNode.value
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node.right = remove(node.right, minLargerNode.value)
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}
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}
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}
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return balance(node)
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}
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private func ceiling(_ node: AVLTreeNode<T>?, _ value: T) -> T? {
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guard let node = node else {
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return nil
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}
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if node.value == value {
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return node.value
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} else if node.value < value {
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return ceiling(node.right, value)
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} else {
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return ceiling(node.left, value) ?? node.value
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}
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}
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private func height(_ node: AVLTreeNode<T>?) -> Int {
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return node?.height ?? 0
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}
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private func balanceFactor(_ node: AVLTreeNode<T>) -> Int {
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return height(node.left) - height(node.right)
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}
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private func updateHeight(_ node: AVLTreeNode<T>) {
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node.height = 1 + max(height(node.left), height(node.right))
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}
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private func rotateRight(_ y: AVLTreeNode<T>) -> AVLTreeNode<T> {
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let x = y.left!
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let T2 = x.right
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x.right = y
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y.left = T2
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updateHeight(y)
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updateHeight(x)
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return x
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}
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private func rotateLeft(_ x: AVLTreeNode<T>) -> AVLTreeNode<T> {
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let y = x.right!
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let T2 = y.left
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y.left = x
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x.right = T2
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updateHeight(x)
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updateHeight(y)
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return y
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}
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private func balance(_ node: AVLTreeNode<T>) -> AVLTreeNode<T> {
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updateHeight(node)
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let balance = balanceFactor(node)
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if balance > 1 {
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if balanceFactor(node.left!) < 0 {
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node.left = rotateLeft(node.left!)
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}
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return rotateRight(node)
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}
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if balance < -1 {
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if balanceFactor(node.right!) > 0 {
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node.right = rotateRight(node.right!)
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}
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return rotateLeft(node)
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}
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return node
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}
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private func minNode(_ node: AVLTreeNode<T>?) -> AVLTreeNode<T>? {
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var current = node
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while current?.left != nil {
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current = current?.left
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}
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return current
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}
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}

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