feat: add swift implementation to lcp problem: No.64 (#3997)

Author: klever34

lcp/LCP 64. 二叉树灯饰/README.md

@@ -258,6 +258,59 @@ func closeLampInTree(root *TreeNode) (ans int) {
 }
 ```
 
+#### Swift
+
+```swift
+/* public class TreeNode {
+*     public var val: Int
+*     public var left: TreeNode?
+*     public var right: TreeNode?
+*     public init(_ val: Int) {
+*         self.val = val
+*         self.left = nil
+*         self.right = nil
+*     }
+* }
+*/
+
+class Solution {
+    func closeLampInTree(_ root: TreeNode?) -> Int {
+        return dfs(root)[0]
+    }
+
+    private func dfs(_ root: TreeNode?) -> [Int] {
+        var ans = [Int](repeating: 0, count: 4)
+        guard let root = root else {
+            return ans
+        }
+
+        let left = dfs(root.left)
+        let right = dfs(root.right)
+
+        let l1 = left[0], l2 = left[1], l3 = left[2], l4 = left[3]
+        let r1 = right[0], r2 = right[1], r3 = right[2], r4 = right[3]
+
+        if root.val != 0 {
+            ans[0] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 1, l4 + r4 + 3)
+            ans[1] = min(l1 + r1 + 2, l2 + r2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[2] = min(l1 + r1, l2 + r2 + 2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[3] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 3, l4 + r4 + 1)
+        } else {
+            ans[0] = min(l1 + r1, l2 + r2 + 2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[1] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 3, l4 + r4 + 1)
+            ans[2] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 1, l4 + r4 + 3)
+            ans[3] = min(l1 + r1 + 2, l2 + r2, l3 + r3 + 2, l4 + r4 + 2)
+        }
+
+        return ans
+    }
+
+    private func min(_ nums: Int...) -> Int {
+        return nums.min() ?? Int.max
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcp/LCP 64. 二叉树灯饰/Solution.swift

@@ -0,0 +1,48 @@
+/* public class TreeNode {
+*     public var val: Int
+*     public var left: TreeNode?
+*     public var right: TreeNode?
+*     public init(_ val: Int) {
+*         self.val = val
+*         self.left = nil
+*         self.right = nil
+*     }
+* }
+*/
+
+class Solution {
+    func closeLampInTree(_ root: TreeNode?) -> Int {
+        return dfs(root)[0]
+    }
+
+    private func dfs(_ root: TreeNode?) -> [Int] {
+        var ans = [Int](repeating: 0, count: 4)
+        guard let root = root else {
+            return ans
+        }
+
+        let left = dfs(root.left)
+        let right = dfs(root.right)
+
+        let l1 = left[0], l2 = left[1], l3 = left[2], l4 = left[3]
+        let r1 = right[0], r2 = right[1], r3 = right[2], r4 = right[3]
+
+        if root.val != 0 {
+            ans[0] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 1, l4 + r4 + 3)
+            ans[1] = min(l1 + r1 + 2, l2 + r2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[2] = min(l1 + r1, l2 + r2 + 2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[3] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 3, l4 + r4 + 1)
+        } else {
+            ans[0] = min(l1 + r1, l2 + r2 + 2, l3 + r3 + 2, l4 + r4 + 2)
+            ans[1] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 3, l4 + r4 + 1)
+            ans[2] = min(l1 + r1 + 1, l2 + r2 + 1, l3 + r3 + 1, l4 + r4 + 3)
+            ans[3] = min(l1 + r1 + 2, l2 + r2, l3 + r3 + 2, l4 + r4 + 2)
+        }
+
+        return ans
+    }
+
+    private func min(_ nums: Int...) -> Int {
+        return nums.min() ?? Int.max
+    }
+}