function solution(dirs) {
  let x = 0;
  let y = 0;

  const dir = dirs.split('');

  let set = [];
  set.push(`${x}${y}`);

  for (let i = 0; i < dir.length; i++) {
    switch (dir[i]) {
      case 'U':
        x += 1;
        break;
      case 'D':
        x -= 1;
        break;
      case 'R':
        y += 1;
        break;
      case 'L':
        y -= 1;
        break;
    }
    if (x < -5 || x > 5 || y < -5 || y > 5) continue;
    if (!set.includes(`${x}${y}`)) set.push(`${x}${y}`);
  }
  return set.length;
}

function solution(dirs) {
  const move = { U: [1, 0], D: [-1, 0], L: [0, -1], R: [0, 1] };
  let set = new Set();
  let now = [0, 0];

  for (let i = 0; i < dirs.length; i++) {
    let nx = now[0] + move[dirs[i]][0];
    let ny = now[1] + move[dirs[i]][1];

    if (nx < -5 || nx > 5 || ny < -5 || ny > 5) continue;
    set.add('' + now[0] + now[1] + nx + ny);
    set.add('' + nx + ny + now[0] + now[1]);
    now = [nx, ny];
  }
  return set.size / 2;
}