feat: add swift implementation to lcof2 problem: No.059 (doocs#3102)

* feat: add swift implementation to lcof2 problem: No.059

* style: format code and docs with prettier

---------

Co-authored-by: Libin YANG <[email protected]>

Author: klever34

lcof2/剑指 Offer II 059. 数据流的第 K 大数值/README.md

@@ -225,6 +225,39 @@ func (h *IntHeap) Top() int {
  */
 ```
 
+#### Swift
+
+```swift
+import Collections
+
+class KthLargest {
+    private var h: Heap<Int>
+    private var size: Int
+
+    init(_ k: Int, _ nums: [Int]) {
+        h = Heap()
+        size = k
+        for x in nums {
+            add(x)
+        }
+    }
+
+    func add(_ val: Int) -> Int {
+        h.insert(val)
+        if h.count > size {
+            h.removeMin()
+        }
+        return h.min!
+    }
+}
+
+/**
+ * Your KthLargest object will be instantiated and called as such:
+ * let obj = KthLargest(k, nums)
+ * let ret_1: Int = obj.add(val)
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 059. 数据流的第 K 大数值/Solution.swift

@@ -0,0 +1,28 @@
+import Collections
+
+class KthLargest {
+    private var h: Heap<Int>
+    private var size: Int
+
+    init(_ k: Int, _ nums: [Int]) {
+        h = Heap()
+        size = k
+        for x in nums {
+            add(x)
+        }
+    }
+    
+    func add(_ val: Int) -> Int {
+        h.insert(val)
+        if h.count > size {
+            h.removeMin()
+        }
+        return h.min!
+    }
+}
+
+/**
+ * Your KthLargest object will be instantiated and called as such:
+ * let obj = KthLargest(k, nums)
+ * let ret_1: Int = obj.add(val)
+ */