feat: add swift implementation to lcof2 problem: No.067 (#3181)

Author: klever34

lcof2/剑指 Offer II 067. 最大的异或/README.md

@@ -235,6 +235,34 @@ func findMaximumXOR(nums []int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func findMaximumXOR(_ numbers: [Int]) -> Int {
+        var max = 0
+        var mask = 0
+
+        for i in stride(from: 30, through: 0, by: -1) {
+            let current = 1 << i
+            mask ^= current
+            var set = Set<Int>()
+            for num in numbers {
+                set.insert(mask & num)
+            }
+            let flag = max | current
+            for prefix in set {
+                if set.contains(prefix ^ flag) {
+                    max = flag
+                    break
+                }
+            }
+        }
+        return max
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 067. 最大的异或/Solution.swift

@@ -0,0 +1,23 @@
+class Solution {
+    func findMaximumXOR(_ numbers: [Int]) -> Int {
+        var max = 0
+        var mask = 0
+
+        for i in stride(from: 30, through: 0, by: -1) {
+            let current = 1 << i
+            mask ^= current
+            var set = Set<Int>()
+            for num in numbers {
+                set.insert(mask & num)
+            }
+            let flag = max | current
+            for prefix in set {
+                if set.contains(prefix ^ flag) {
+                    max = flag
+                    break
+                }
+            }
+        }
+        return max
+    }
+}