Feature/stack queue

Package.swift

@@ -5,9 +5,6 @@ import PackageDescription
 
 let package = Package(
     name: "XDataStructures",
-    platforms: [
-        .macOS(.v10_14), .iOS(.v13), .tvOS(.v13)
-    ],
     products: [
         // Products define the executables and libraries a package produces, and make them visible to other packages.
         .library(

Sources/XDataStructures/Queue.swift

@@ -0,0 +1,33 @@
+//
+//  File.swift
+//  
+//
+//  Created by BrainX Technologies IOS 4 on 25/02/2021.
+//
+
+import Foundation
+
+public struct Queue<T> {
+
+    //MARK: List
+    fileprivate var items: [T] = []
+
+    //MARK: Initializers
+    public init(){}
+
+    //MARK: Methods
+    public func peek() -> T? {
+        return items.last
+    }
+
+    public mutating func enqueue(_ element: T) {
+        items.append(element)
+    }
+
+    public mutating func dequeue() -> T? {
+        guard let _ = items.last else {
+            return nil
+        }
+        return items.removeLast()
+    }
+}

Sources/XDataStructures/Stack.swift

@@ -0,0 +1,33 @@
+//
+//  File.swift
+//  
+//
+//  Created by BrainX Technologies IOS 4 on 25/02/2021.
+//
+
+import Foundation
+
+public struct Stack <T> {
+
+    //MARK: List
+    fileprivate var items: [T] = []
+
+    //MARK: Initializers
+    public init(){}
+
+    //MARK: Methods
+    public func peek() -> T? {
+        return items.first
+    }
+
+    public mutating func push(_ element: T) {
+        items.insert(element, at: 0)
+    }
+
+    public mutating func pop() -> T? {
+        guard let _ = items.first else {
+            return nil
+        }
+        return items.removeFirst()
+    }
+}

Tests/XDataStructuresTests/QueueTest/QueueTest.swift

@@ -0,0 +1,34 @@
+//
+//  QueueTest.swift
+//
+//
+//  Created by BrainX Technologies IOS 4 on 25/02/2021.
+//
+
+import XCTest
+@testable import XDataStructures
+
+class QueueTest: XCTest {
+
+    func testDequeueFromNonEmpty() {
+        var queue: Queue = Queue<Int>()
+        queue.enqueue(2)
+        XCTAssertNotNil(queue.dequeue())
+    }
+
+    func testPopFromEmpty() {
+        var queue: Queue = Queue<Int>()
+        XCTAssertNil(queue.dequeue())
+    }
+
+    func testPeakFromNonEmpty() {
+        var queue: Queue = Queue<Int>()
+        queue.enqueue(2)
+        XCTAssertNotNil(queue.dequeue())
+    }
+
+    func testPeakFromEmpty() {
+        var queue: Queue = Queue<Int>()
+        XCTAssertNil(queue.dequeue())
+    }
+}

Tests/XDataStructuresTests/StackTest/StackTest.swift

@@ -0,0 +1,34 @@
+//
+//  StackTest.swift
+//
+//
+//  Created by BrainX Technologies IOS 4 on 25/02/2021.
+//
+
+import XCTest
+@testable import XDataStructures
+
+class StackTest: XCTest {
+
+    func testPopFromNonEmpty() {
+        var stack: Stack = Stack<Int>()
+        stack.push(2)
+        XCTAssertNotNil(stack.pop())
+    }
+
+    func testPopFromEmpty() {
+        var stack: Stack = Stack<Int>()
+        XCTAssertNil(stack.pop())
+    }
+
+    func testPeakFromNonEmpty() {
+        var stack: Stack = Stack<Int>()
+        stack.push(2)
+        XCTAssertNotNil(stack.peek())
+    }
+
+    func testPeakFromEmpty() {
+        let stack: Stack = Stack<Int>()
+        XCTAssertNil(stack.peek())
+    }
+}

Tests/XDataStructuresTests/XCTestManifests.swift

@@ -3,7 +3,8 @@ import XCTest
 #if !canImport(ObjectiveC)
 public func allTests() -> [XCTestCaseEntry] {
     return [
-        testCase(XDataStructuresTests.allTests),
+        testCase(XDataStructuresTests.StackTest),
+        testCase(XDataStructuresTests.QueueTest)
     ]
 }
 #endif