Swift Data Structures

dataStructures.Swift

// Stack
struct Stack<T> {
    var items = [T]()
    
    mutating func push(item: T) {
        items.append(item)
    }
    
    mutating func pop() -> T {
        return items.removeLast()
    }
}

var stackStrings = Stack<String>()
stackInts.push("Hello")
stackInts.push("World")
stackInts.push("Swift")
stackInts.push("Stack")

print("pop: \(stackStrings.pop())")


// Tree

class TreeNode<T: Comparable> {
 
    var val: T?
    var leftNode: TreeNode?
    var rightNode: TreeNode?
     
    //add item based on its value
    func addNode(val: T) {
        
        if (self.val == nil) {
            self.val = val
            print("Added Head")
            return
        }
        
        if (val < self.val) {
            
            if let left = self.leftNode {
              left.addNode(val)
            } else {
                let newLeft = TreeNode()
                newLeft.val = val
                self.leftNode = newLeft
                print("Added Left")
            }
        }

        if (val > self.val) {
            
            if let right = self.rightNode {
                right.addNode(val)
            } else {
                let newRight = TreeNode()
                newRight.val = val
                self.rightNode = newRight
                print("Added Right")
            }   
        }
    }
}

let numbers: Array<Int> = [8, 3, 5, 2, 7, 9, 13, 16, 10, 22]
var root = TreeNode<Int>()

for n in numbers {
    print(n)
    root.addNode(n)
}