Plays Snake game at dskang.com/snake/

dksnake.js

// Computer assisted snake!
// Paste this into the JS console at http://dskang.com/snake/ to play and win!

function getX() {
  var head = gSnake.getHead();
  var x = head.x / 20;
  return x;
}

function getY() {
  var head = gSnake.getHead();
  var y = (head.y - 40) / 20;
  return y;
}

function foodX() {
  return gFood.location.x / 20;
}

function foodY() {
  return (gFood.location.y - 40) / 20;
}

function amWound() {
  // Am I wound up enough to safely move down?
  var myY = getY();
  for (var i = 0; i < gSnake.body.length; i++) {
    var bodyX = (gSnake.body[i].x) / 20;
    var bodyY = (gSnake.body[i].y - 40) / 20;
    if (bodyX > 0 && (bodyY == myY + 1 || bodyY == myY + 2 || bodyY == myY + 3)) {
      return false;  // you might run into yourself if you go down; be careful!
    }
  }
  return true;
}

function getmove() {
  var x = getX();
  var y = getY();

  // Save time by moving down toward food when there's room to do so.
  if (amWound()) {
    if (x != 0 && y + 1 < foodY()) {
      return DOWN;
    } else if (x != 0 && y < 27 && foodY() < y) {
      return DOWN;
    }
  }

  // By default we move in a zigzag fashion:
  // - right on even rows
  // - left on odd rows
  // - up the left hand column to the top
  if (x == 0 && y == 0) {
    return RIGHT;
  } else if (y == 0 && x == 29) {
    return DOWN;
  } else if (y == 0) {
    return RIGHT;
  } else if (x == 0) {
    return UP;
  } else if (x == 29 && y < 27 && y % 2 == 0) {
    return DOWN;
  } else if (y < 27 && y % 2 == 0) {
    return RIGHT;
  } else if (x == 1 && y < 27 && y % 2 == 1) {
    return DOWN;
  } else if (y < 27 && y % 2 == 1) {
    return LEFT;
  } else if (y == 27) {
    return LEFT;
  }
}

var lastX = getX();
var lastY = getY();
var lastMove = RIGHT;

function step() {
  var newX = getX();
  var newY = getY();
  var newMove = getmove();

  if ((newX != lastX || newY != lastY) && lastMove != newMove) {
    lastMove = newMove;
    gSnake.directionQueue = [newMove];
    console.log(gSnake.directionQueue);
  }

  lastX = newX;
  lastY = newY;
}

var interval;
clearInterval(interval);
interval = setInterval(step, 50);