Maximum Points You Can Obtain from Cards LeetCode solution in JavaScript

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/**
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 * @param {number[]} cardPoints
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 * @param {number} k
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 * @return {number}
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 */
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// Obtaining k cards from the beginning or end of the row for the largest sum, meaning leaving the
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// array with n-k adjacent cards with the min sum
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// therefore, this transform the problem to finding the minSum of subarray of length n-k
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// we use slide window to calculate the minSubArraySum
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var maxScore = function (cardPoints, k) {
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  const n = cardPoints.length,
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    d = n - k; // d is the window length
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  let sum = 0;
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  for (let i = 0; i < d; i++) {
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    sum += cardPoints[i];
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  }
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  let minWindowSum = sum,
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    totalSum = sum;
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  console.log(sum);
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  for (let i = d; i < n; i++) {
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    // the sum of the next window will the the sum of previous window + the next card (the end card of the next window) - the beginning card of the previous window
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    sum += cardPoints[i] - cardPoints[i - d];
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    minWindowSum = Math.min(minWindowSum, sum);
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    totalSum += cardPoints[i];
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  }
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  // the ans will be the sum of all cards - the sum of min subArray
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  return totalSum - minWindowSum;
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};