let step;

let ready;

let delimiter = ' ';

​

this.focus();

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  textSize(80);

  fill('white');

  noStroke();

  initData();

}

​

function initData() {

//  track = ['A', 'B', 'C', 'D', 'E', 'F'];

  track = [1, 2, 3, 4, 5, 6];

//  track = [0, 0, 1, 2, 2, 2, 5, 5]; // Kömal_2025-01_841

  textAlign(CENTER, TOP);

  step = 1;

  ready = false;

  noLoop();

}

​

function displayData() {

  background('black');

  let s = '';

  for (let i = 0; i < track.length - 1; i++) {

    s = s + track[i] + delimiter;

  }

  s = s + track[track.length - 1];

  text('# ' + step, width / 2, 0);

  text(s, width / 2, height / 2);

}

​

function nextPermutation(left = 0, right = 0) {

  // left  = Number of DO-NOT-TOUCH element(s) from left

  // right = Number of DO-NOT-TOUCH element(s) from right

  let startPos = track.length - 1 - right;

  // STEP1: Find the Pivot

  let i = startPos;

  while (i > 0 && track[i - 1] >= track[i]) { i-- }

  if (i <= left) { return false }

  // STEP2: Find rightmost element (RME) greater than the Pivot

  let j = startPos;

  while (track[j] <= track[i - 1]) { j-- }

  // STEP3: Swap the Pivot and RME

  let temp = track[i - 1];

  track[i - 1] = track[j];

  track[j] = temp;

  // STEP4: Reverse suffix

  j = startPos;

  while (i < j) {

    temp = track[i];

    track[i] = track[j];

    track[j] = temp;

    i++;

    j--;

  }

  return true;

}

​

function keyPressed() {

  if(keyCode === ENTER) {

    if (isLooping()) { noLoop(); return; }

    if (ready) {

      initData();

      displayData();

    } else { loop() }

  }

  if(keyCode === ESCAPE & !isLooping() & !ready) {

    oneStep();

  }

}

​

function oneStep() {

  displayData();

  if (nextPermutation() == false) {

    ready = true;

    noLoop();

    textAlign(CENTER, BOTTOM);

    text('READY', width / 2, height);

  }

  step++;

}

​

function draw() {

  oneStep();

}