K-Concatenation Maximum Sum LeetCode solution in JavaScript

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var kConcatenationMaxSum = function (arr, k) {
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  var MOD = 1000000007;
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  let sum = arr.reduce((a, b) => a + b);
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  if (k > 1) arr.push(...arr);
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  let temp = 0,
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    result = 0;
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  for (i = 0; i < arr.length; i++) {
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    temp = Math.max(arr[i], arr[i] + temp);
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    if (temp > result) result = temp;
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  }
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  return sum > 0 && k > 2 ? (result + sum * (k - 2)) % MOD : result % MOD;
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};