let cWidth = 1200, cHeight = 400;

const size = 100;

let sleepTime = 0;

​

let values = new Array(size);

let state = new Array(size);

let finished = false;

​

function setup()

{

    createCanvas(cWidth, cHeight);

    const low = 10, high = cHeight;

    for (let i = 0; i < size; ++i)

    {

        // values[i] = int(random(low, high))

        values[i] = low + (high - low) * i / size;

        state[i] = -1;

    }

    shuffle(values);

    display();

    const SORT = async () =>

    {

        await selectionsort(values);

        finished = true;

    }

    SORT();

}

​

function draw()

{

    display()

}

​

const w = cWidth / size;

function display()

{

    background(0)

    if (finished)

    {

        fill(0, 255, 0)

        for (let i = 0; i < size; ++i)

            rect(w * i, height - values[i], w, values[i])

        noLoop();

        return;

    }

​

    for (let i = 0; i < size; ++i)

    {

        switch (state[i])

        {

            case 1://pointer

                fill(255, 0, 0);

                break;

            case 2:

                fill(0, 0, 255);//current element

                break;

            case 3:

                fill(0, 255, 0);//sorted

                break;

            default:

                fill(180);

                break;

        }

        rect(w * i, height - values[i], w, values[i])

    }

}

​

async function selectionsort(a)

{

    for (let i = 0; i < a.length; ++i)

    {

        let min_idx = i;

        state[i] = 2;

        for (let j = i + 1; j < a.length; ++j)

        {

            state[j] = 1;

            if (a[j] < a[min_idx])

                min_idx = j;

            await sleep(sleepTime);

            state[j] = 0;

        }

        swap(a, min_idx, i);

        state[i] = 3;

    }

}

​

function sleep(ms)

{

    return new Promise(resolve => setTimeout(resolve, ms));

}

​

function swap(a, i, j)

{

    let t = a[i];

    a[i] = a[j];

    a[j] = t;

}

​

//Fisher-Yates Algorithm

const shuffle = array =>

{

    for (let i = array.length - 1; i > 0; i--)

    {

        const j = Math.floor(Math.random() * (i + 1));

        const temp = array[i];

        array[i] = array[j];

        array[j] = temp;

    }

}