Minimum Insertions to Balance a Parentheses String LeetCode solution in JavaScript

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var minInsertions = function (s) {
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  let rightNeeded = 0;
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  let leftNeeded = 0;
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  for (const char of s) {
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    if (char === "(") {
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      if (rightNeeded % 2 === 0) {
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        rightNeeded += 2;
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      } else {
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        rightNeeded++;
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        leftNeeded++;
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      }
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    } else {
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      rightNeeded--;
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      if (rightNeeded === -1) {
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        leftNeeded++;
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        rightNeeded = 1;
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      }
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    }
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  }
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  return leftNeeded + rightNeeded;
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};