Number of Ways to Paint N × 3 Grid LeetCode solution in JavaScript

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/**
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 * @param {number} n
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 * @return {number}
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 */
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var numOfWays = function (n) {
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  const mod = Math.pow(10, 9) + 7;
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  const dp212 = [6];
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  const dp123 = [6];
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  for (let i = 1; i < n; i++) {
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    // two sides same
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    dp212[i] = (dp212[i - 1] * (5 - 2) + dp123[i - 1] * (6 - 2 - 1 - 1)) % mod;
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    // three different colors
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    dp123[i] =
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      (dp123[i - 1] * (5 - 1 - 1 - 1) + dp212[i - 1] * (6 - 2 - 2)) % mod;
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  }
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  return (dp212[n - 1] + dp123[n - 1]) % mod;
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};