SwiftAnimations

Description

SwiftAnimations it's a library created to visualize changes to array. It might be a helpful tool for studying sorting algorithms.

You can find out source code with a playground here:
https://github.com/izotx/SwiftAnimations

The source code contains example of using the library with bubble sort.

Usage

Library comes with several handy methods for visualizing changes:

swapElements // Responsible for swapping elements in array
selectElements // Selecting and deselecting
insertAtIndex moves element from index a to b and shifts array 
up, down, rightLeft, for more granular control over animations

Each of the methods creates and adds an animation to the list of animations.

[IMAGE: https://github.com/izotx/SwiftAnimations/raw/master/bubbleSortAnimation.gif]

Here is original Bubble Sort code copied from awesome Swift Algorithms Club: https://github.com/raywenderlich/swift-algorithm-club

func originalBubbleSort(_  array:inout [Int]){
    for _ in 0.. = ArrayAnimationView(frame: CGRect(x: 0, y: 0, width: 380, height: 50))

1. Add it to the view

    self.view.addSubview(visualizer) 

1. Display array

    var a = [3,2,0,8,5,10,6,9]
    visualizer.displayArray(a)

1. Create an extension with animation:
   The key point here is recognize what algorithm is doing, and visualize it. For example the code below:

   let tmp = array[j-1]
    array[j-1] = array[j]
    array[j] = tmp

is performing swap of two elements of the array. The code below is a full example of animations

1. Animate changes
   visualizer.resetAnimations()
   visualizer.bubbleSort(&a)
   visualizer.animateChanges()

extension  ArrayAnimationView{
    func bubbleSort(_  array:inout [Int]){
        for _ in 0..<array.count {
            for j in 1..<array.count {
                //Compare two elements: so slide down
                if array[j] < array[j-1] {
                    let tmp = array[j-1]
                    array[j-1] = array[j]
                    array[j] = tmp
                    swapElements(arrayElements[j], arrayElements[j-1], j, j-1)
                }
                else{

                selectElements([arrayElements[j], arrayElements[j-1]], [true,true])
                down([arrayElements[j], arrayElements[j-1]])
                up([arrayElements[j], arrayElements[j-1]])

                selectElements([arrayElements[j], arrayElements[j-1]], [false,false])

                }
            }
        }
    }
}