Count Number of Ways to Place Houses LeetCode solution in JavaScript

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const mod = 10 ** 9 + 7;
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var countHousePlacements = function (n) {
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  let prev2 = 1;
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  let prev1 = 1;
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  let ways = 2;
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  for (let i = 2; i <= n; i++) {
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    prev2 = prev1;
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    prev1 = ways;
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    ways = (prev1 + prev2) % mod;
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  }
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  return ways ** 2 % mod;
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};