Binary Tree Right Side View LeetCode solution in JavaScript

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var rightSideView = function (root) {
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  if (!root) return [];
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  let ans = [];
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  let queue = [root];
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  while (queue.length > 0) {
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    let queueLength = queue.length;
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    // As we are giving priority to right node,
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    // first node will always be the one that we want in output
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    ans.push(queue[0].val);
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    for (let i = 0; i < queueLength; i++) {
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      // Ignore TC of queue.shift (assuming we have queue implementation with O(1) TC)
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      let current = queue.shift();
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      // Always give priority to right node
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      if (current.right) queue.push(current.right);
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      if (current.left) queue.push(current.left);
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    }
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  }
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  return ans;
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};