feat: add swift implementation to lcci problem: No.03.05 (doocs#2643)

Author: klever34

lcci/03.05.Sort of Stacks/README.md

@@ -314,6 +314,49 @@ impl SortedStack {
  */
 ```
 
+```swift
+class SortedStack {
+    private var stk: [Int] = []
+
+    init() {}
+
+    func push(_ val: Int) {
+        var temp: [Int] = []
+        while let top = stk.last, top < val {
+            temp.append(stk.removeLast())
+        }
+        stk.append(val)
+        while let last = temp.popLast() {
+            stk.append(last)
+        }
+    }
+
+    func pop() {
+        if !isEmpty() {
+            stk.removeLast()
+        }
+    }
+
+    func peek() -> Int {
+        return isEmpty() ? -1 : stk.last!
+    }
+
+    func isEmpty() -> Bool {
+        return stk.isEmpty
+    }
+}
+
+/**
+ * Your SortedStack object will be instantiated and called as such:
+ * let obj = new SortedStack();
+ * obj.push(val);
+ * obj.pop();
+ * let param_3 = obj.peek();
+ * var myVar: Bool;
+ * myVar = obj.isEmpty();
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- end -->

lcci/03.05.Sort of Stacks/README_EN.md

@@ -327,6 +327,49 @@ impl SortedStack {
  */
 ```
 
+```swift
+class SortedStack {
+    private var stk: [Int] = []
+
+    init() {}
+
+    func push(_ val: Int) {
+        var temp: [Int] = []
+        while let top = stk.last, top < val {
+            temp.append(stk.removeLast())
+        }
+        stk.append(val)
+        while let last = temp.popLast() {
+            stk.append(last)
+        }
+    }
+
+    func pop() {
+        if !isEmpty() {
+            stk.removeLast()
+        }
+    }
+
+    func peek() -> Int {
+        return isEmpty() ? -1 : stk.last!
+    }
+
+    func isEmpty() -> Bool {
+        return stk.isEmpty
+    }
+}
+
+/**
+ * Your SortedStack object will be instantiated and called as such:
+ * let obj = new SortedStack();
+ * obj.push(val);
+ * obj.pop();
+ * let param_3 = obj.peek();
+ * var myVar: Bool;
+ * myVar = obj.isEmpty();
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- end -->

lcci/03.05.Sort of Stacks/Solution.swift

@@ -0,0 +1,40 @@
+class SortedStack {
+    private var stk: [Int] = []
+
+    init() {}
+
+    func push(_ val: Int) {
+        var temp: [Int] = []
+        while let top = stk.last, top < val {
+            temp.append(stk.removeLast())
+        }
+        stk.append(val)
+        while let last = temp.popLast() {
+            stk.append(last)
+        }
+    }
+
+    func pop() {
+        if !isEmpty() {
+            stk.removeLast()
+        }
+    }
+
+    func peek() -> Int {
+        return isEmpty() ? -1 : stk.last!
+    }
+
+    func isEmpty() -> Bool {
+        return stk.isEmpty
+    }
+}
+
+/**
+ * Your SortedStack object will be instantiated and called as such:
+ * let obj = new SortedStack();
+ * obj.push(val);
+ * obj.pop();
+ * let param_3 = obj.peek();
+ * var myVar: Bool;
+ * myVar = obj.isEmpty();
+ */