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var maxDistance = function (colors) {
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  // using two pointers from start and end
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  // Time complexity O(n)
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  // Space complexity O(1)
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  const start = 0;
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  const end = colors.length - 1;
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  // maximum distance possible is length of arr, so start with two pointer
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  // one at the start and one at the end
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  const startColor = colors[start];
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  const endColor = colors[end];
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  // base condition, to check if they are not already equal
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  if (startColor !== endColor) {
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    return end;
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  }
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  // move the forward pointer till we find the differend color
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  let forwardPtr = start;
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  while (startColor === colors[forwardPtr]) {
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    ++forwardPtr;
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  }
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  // move the backward pointer till we find the differend color
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  let backwardPtr = end;
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  while (endColor === colors[backwardPtr]) {
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    --backwardPtr;
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  }
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  // Till here, We already know that startColor === endColor
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  // hence we did two things,
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  // 1. we kept startColor fixed and moved backwardPtr till we find different color
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  // 2. similarly, we kept endColor fixed and moved the forwardPtr till we find the different color.
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  // we will return the max different out of two now.
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  return Math.max(Math.abs(start - backwardPtr), Math.abs(end - forwardPtr));
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};