Circular Array Loop LeetCode solution in JavaScript

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var circularArrayLoop = function (nums) {
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  // cannot be a cycle if there are less than 2 elements
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  const numsLen = nums.length;
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  if (numsLen < 2) return false;
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  // init visited array
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  const visited = Array(numsLen).fill(false);
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  // check each index to see if a cycle can be produced
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  for (let i = 0; i < numsLen; i++) {
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    if (visited[i]) continue;
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    visited[i] = true;
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    // determine initial direction
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    const isPositive = nums[i] > 0;
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    // reset which indices were visited after each iteration
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    const visitedPerIdx = Array(numsLen).fill(false);
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    // reset cycle length and current index after each iteration
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    let cycleLen = 0,
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      currIdx = i;
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    // loop while cycle is valid
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    while (true) {
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      // break if current index moves cycle in opposite direction
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      if (isPositive !== nums[currIdx] > 0) break;
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      // calc next valid index
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      let nextIdx = (currIdx + nums[currIdx]) % numsLen;
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      // map negative index to a positive index
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      if (nextIdx < 0) nextIdx += numsLen;
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      // break if cycle points to same index
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      if (currIdx === nextIdx) break;
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      cycleLen++;
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      // a cycle is found when the index has already been visited in the current outer iteration, and
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      // the cycle length is greater than 1.
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      if (visitedPerIdx[nextIdx] && cycleLen > 1) return true;
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      visitedPerIdx[nextIdx] = true;
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      visited[nextIdx] = true;
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      // set curr index to new index
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      currIdx = nextIdx;
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    }
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  }
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  return false;
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};