Write a function that prints the matrix to the standard output (stdout) on a single line starting in the upper-left corner and continuing clockwise, in circles, from exterior towards interior.

snake.js

var snakePrint = function(numbers, width) {
  var xyTo1D = function(x, y) {
    return y * width + x;
  };

  var matrix = numbers.split(','),
    directions = [[1, 0], [0, 1], [-1, 0], [0, -1]],
    output = '',
    snake = {
      length: 0,
      x: 0,
      y: 0,
      direction: 0,

      walk: function() {
        var index = xyTo1D(this.x, this.y);
        output += matrix[index] + ' ';
        matrix[index] = undefined;
        this.length++;
        this.x += directions[this.direction][0];
        this.y += directions[this.direction][1];
      },

      turnRight: function () {
        this.direction = (this.direction + 1) % 4;
      },

      isBlocked: function () {
        var x1 = this.x + directions[this.direction][0];
        var y1 = this.y + directions[this.direction][1];
        return x1 == width || y1 == width || matrix[xyTo1D(x1, y1)] === undefined;
      }
    };

  while (snake.length < width * width) {
    if (snake.isBlocked()) {
      snake.turnRight();
    }
    snake.walk();
  }
  
  console.log(output);
};