Minimum Moves to Reach Target with Rotations LeetCode solution in JavaScript

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/**
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 * @param {number[][]} grid
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 * @return {number}
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 */
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var minimumMoves = function (grid) {
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  const len = grid.length;
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  const initPosition = [0, true, 1];
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  const visited = new Set([initPosition.join()]);
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  const queue = new Queue();
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  initPosition.push(0);
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  queue.enqueue(initPosition);
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  while (!queue.isEmpty()) {
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    let [row, isHorizontal, col, numMoves] = queue.dequeue();
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    if (row + col === len * 2 - 2 && isHorizontal) return numMoves;
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    numMoves++;
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    const positions = [];
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    if (isHorizontal) {
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      if (grid[row][col + 1] === 0) {
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        positions.push([row, true, col + 1]);
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      }
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      if (
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        row + 1 < len &&
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        grid[row + 1][col - 1] === 0 &&
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        grid[row + 1][col] === 0
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      ) {
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        positions.push([row + 1, true, col]);
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        positions.push([row + 1, false, col - 1]);
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      }
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    } else {
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      if (row + 1 < len && grid[row + 1][col] === 0) {
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        positions.push([row + 1, false, col]);
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      }
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      if (row > 0 && grid[row - 1][col + 1] === 0 && grid[row][col + 1] === 0) {
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        positions.push([row, false, col + 1]);
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        positions.push([row - 1, true, col + 1]);
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      }
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    }
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    for (let position of positions) {
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      const str = position.join();
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      if (visited.has(str)) continue;
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      visited.add(str);
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      position.push(numMoves);
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      queue.enqueue(position);
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    }
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  }
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  return -1;
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};
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class Queue {
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  constructor() {
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    this.head = { next: null };
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    this.tail = this.head;
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  }
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  isEmpty() {
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    return this.head.next === null;
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  }
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  dequeue() {
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    const { value } = this.head.next;
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    this.head = this.head.next;
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    return value;
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  }
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  enqueue(value) {
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    this.tail.next = { value, next: null };
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    this.tail = this.tail.next;
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  }
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}