Insertion Sort List LeetCode solution in JavaScript

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/**
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 * Definition for singly-linked list.
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 * function ListNode(val, next) {
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 *     this.val = (val===undefined ? 0 : val)
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 *     this.next = (next===undefined ? null : next)
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 * }
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 */
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/**
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 * @param {ListNode} head
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 * @return {ListNode}
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 */
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var insertionSortList = function (head) {
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  let ptr = head;
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  while (ptr.next !== null) {
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    if (ptr.val <= ptr.next.val) ptr = ptr.next;
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    else {
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      let temp = ptr.next;
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      ptr.next = ptr.next.next;
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      if (temp.val < head.val) {
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        temp.next = head;
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        head = temp;
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      } else {
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        let ptr2 = head;
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        while (ptr2.next != null && temp.val >= ptr2.next.val) {
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          ptr2 = ptr2.next;
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        }
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        temp.next = ptr2.next;
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        ptr2.next = temp;
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      }
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    }
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  }
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  return head;
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};