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iOS

Posted by Joyce Ryu
Joyce Ryu
1,124 Points

Queue Problem solving! ASAP what goes in the line? 

struct Queue {
    var queueArray:[String] = []

    mutating func enqueue (element:String) {
        // ...
    }
    mutating func dequeue() -> String {
       // ...
        return returnValue
    }
}

var newQueue = Queue()
newQueue.enqueue("Leonard")
newQueue.enqueue("Sheldon")

newQueue.enqueue("Penny")
newQueue.enqueue("Howard")
newQueue.enqueue("Rajesh")
let firstOne = newQueue.dequeue()
Martin Wildfeuer
Martin Wildfeuer
Courses Plus Student 11,071 Points

Could you please explain your question/problem in more detail? I have no clue :|

1 Answer

Richard Lu
Richard Lu
20,185 Points
Richard Lu
Richard Lu
20,185 Points

Hey Hee Eun,

If the question is to fill in the lines commented out, here's your solution. 

struct Queue {
    var queueArray:[String] = []

    mutating func enqueue(element:String) {
        queueArray.append(element)
    }
    mutating func dequeue() -> String? {
        return queueArray.count > 0 ? queueArray.removeFirst() : nil
    }
}

var newQueue = Queue()
newQueue.enqueue("Leonard")
newQueue.enqueue("Sheldon")

newQueue.enqueue("Penny")
newQueue.enqueue("Howard")
newQueue.enqueue("Rajesh")
let firstOne = newQueue.dequeue()

Enjoy! :)

Martin Wildfeuer
Martin Wildfeuer
Courses Plus Student 11,071 Points

I see! dequeue might have to be sthg. like

mutating func dequeue() -> String? {
    return !test.isEmpty ? test.removeFirst() : nil
}

in order to remove that item from the queue.

Richard Lu
Richard Lu
20,185 Points

Thanks for pointing that out Martin Wildfeuer, I really appreciate it :). The full solution is located here:

Solution

Martin Wildfeuer
Martin Wildfeuer
Courses Plus Student 11,071 Points

Sure thing, Richard Lu! I appreciate you taking the time to write the Queue/Stack thing. To be honest, not sure if I had done this in this case ;)