题解 | #链表的奇偶重排#

/*
 * function ListNode(x){
 *   this.val = x;
 *   this.next = null;
 * }
 */
/**
 * 用一个变量i标记奇偶，遍历链表，分成两个链表，分别记住头尾，最后再连起来。注意要把偶数尾部的next置为null
 */
function oddEvenList( head ) {

    let head_odd = new ListNode(-1);
    let head_even = new ListNode(-1);
    let last_odd = head_odd;
    let last_even = head_even;
    let i=1;
    while(head){
        
        if(i%2==1){
            last_odd.next = head;
            last_odd=head;
        }
        else{
            last_even.next = head;
            last_even=head;
        }
        
        head = head.next;
        i++;
    }
    last_even.next=null;
    last_odd.next=head_even.next;
    return head_odd.next;
}
module.exports = {
    oddEvenList : oddEvenList
};