Minimum Swaps to Group All 1's Together II LeetCode solution in JavaScript

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var minSwaps = function (nums) {
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  const MAX = Number.MAX_SAFE_INTEGER;
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  let ones = nums.reduce((acc, bit) => acc + bit, 0);
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  const doubledNums = nums.concat(nums.slice(0, nums.length - 1));
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  let minSwap = MAX;
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  let left = 0;
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  let onesWithinWindow = 0;
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  for (let i = 0; i < doubledNums.length; ++i) {
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    const rightBit = doubledNums[i];
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    if (rightBit === 1) onesWithinWindow += 1;
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    if (i >= ones) {
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      const leftBit = doubledNums[left];
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      if (leftBit === 1) onesWithinWindow -= 1;
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      ++left;
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    }
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    if (i + 1 >= ones) minSwap = Math.min(minSwap, ones - onesWithinWindow);
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  }
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  return minSwap;
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};