feat: add swift implementation to lcci problem: No.05.04 (doocs#2668)

klever34 · web-flow · commit e31dd7a3aae1 · 2024-04-26T16:14:16.000+08:00
diff --git a/lcci/05.04.Closed Number/README.md b/lcci/05.04.Closed Number/README.md
@@ -204,6 +204,50 @@ function findClosedNumbers(num: number): number[] {
 }
 ```
 
+```swift
+class Solution {
+    func findClosedNumbers(_ num: Int) -> [Int] {
+        var ans = [-1, -1]
+        let dirs = [0, 1, 0]
+
+        for p in 0..<2 {
+            let a = dirs[p], b = dirs[p + 1]
+            var x = num
+            var found = false
+
+            for i in 1..<31 {
+                if ((x >> i) & 1) == a && ((x >> (i - 1)) & 1) == b {
+                    x ^= (1 << i)
+                    x ^= (1 << (i - 1))
+
+                    var j = 0, k = i - 2
+                    while j < k {
+                        while j < k && ((x >> j) & 1) == b {
+                            j += 1
+                        }
+                        while j < k && ((x >> k) & 1) == a {
+                            k -= 1
+                        }
+                        if j < k {
+                            x ^= (1 << j)
+                            x ^= (1 << k)
+                        }
+                    }
+                    ans[p] = x
+                    found = true
+                    break
+                }
+            }
+            if !found {
+                ans[p] = -1
+            }
+        }
+
+        return ans
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/05.04.Closed Number/README_EN.md b/lcci/05.04.Closed Number/README_EN.md
@@ -208,6 +208,50 @@ function findClosedNumbers(num: number): number[] {
 }
 ```
 
+```swift
+class Solution {
+    func findClosedNumbers(_ num: Int) -> [Int] {
+        var ans = [-1, -1]
+        let dirs = [0, 1, 0]
+
+        for p in 0..<2 {
+            let a = dirs[p], b = dirs[p + 1]
+            var x = num
+            var found = false
+
+            for i in 1..<31 {
+                if ((x >> i) & 1) == a && ((x >> (i - 1)) & 1) == b {
+                    x ^= (1 << i)
+                    x ^= (1 << (i - 1))
+
+                    var j = 0, k = i - 2
+                    while j < k {
+                        while j < k && ((x >> j) & 1) == b {
+                            j += 1
+                        }
+                        while j < k && ((x >> k) & 1) == a {
+                            k -= 1
+                        }
+                        if j < k {
+                            x ^= (1 << j)
+                            x ^= (1 << k)
+                        }
+                    }
+                    ans[p] = x
+                    found = true
+                    break
+                }
+            }
+            if !found {
+                ans[p] = -1
+            }
+        }
+
+        return ans
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/05.04.Closed Number/Solution.swift b/lcci/05.04.Closed Number/Solution.swift
@@ -0,0 +1,41 @@
+class Solution {
+    func findClosedNumbers(_ num: Int) -> [Int] {
+        var ans = [-1, -1]
+        let dirs = [0, 1, 0]
+        
+        for p in 0..<2 {
+            let a = dirs[p], b = dirs[p + 1]
+            var x = num
+            var found = false
+            
+            for i in 1..<31 {
+                if ((x >> i) & 1) == a && ((x >> (i - 1)) & 1) == b {
+                    x ^= (1 << i)
+                    x ^= (1 << (i - 1))
+                    
+                    var j = 0, k = i - 2
+                    while j < k {
+                        while j < k && ((x >> j) & 1) == b {
+                            j += 1
+                        }
+                        while j < k && ((x >> k) & 1) == a {
+                            k -= 1
+                        }
+                        if j < k {
+                            x ^= (1 << j)
+                            x ^= (1 << k)
+                        }
+                    }
+                    ans[p] = x
+                    found = true
+                    break
+                }
+            }
+            if !found {
+                ans[p] = -1
+            }
+        }
+        
+        return ans
+    }
+}
