feat: add swift implementation to lcci problem: No.17.14 (#2785)

Author: klever34

lcci/17.14.Smallest K/README.md

@@ -70,6 +70,16 @@ func smallestK(arr []int, k int) []int {
 }
 ```
 
+```swift
+class Solution {
+    func smallestK(_ arr: [Int], _ k: Int) -> [Int] {
+        guard k > 0 else { return [] }
+        let sortedArray = arr.sorted()
+        return Array(sortedArray.prefix(k))
+    }
+}
+```
+
 <!-- tabs:end -->
 
 ### 方法二：优先队列（大根堆）

lcci/17.14.Smallest K/README_EN.md

@@ -69,6 +69,16 @@ func smallestK(arr []int, k int) []int {
 }
 ```
 
+```swift
+class Solution {
+    func smallestK(_ arr: [Int], _ k: Int) -> [Int] {
+        guard k > 0 else { return [] }
+        let sortedArray = arr.sorted()
+        return Array(sortedArray.prefix(k))
+    }
+}
+```
+
 <!-- tabs:end -->
 
 ### Solution 2

lcci/17.14.Smallest K/Solution.swift

@@ -0,0 +1,7 @@
+class Solution {
+    func smallestK(_ arr: [Int], _ k: Int) -> [Int] {
+        guard k > 0 else { return [] }
+        let sortedArray = arr.sorted()
+        return Array(sortedArray.prefix(k))
+    }
+}