题解 | #反转链表#

/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function ReverseList(pHead)
{
    // write code here
    if(pHead == null || pHead.next == null){
        return pHead
    }
    //p1改变后的 头指针 p2尾指针 从左到右改变指针方向
    let p1=null,p2=null
    while(pHead != null){
        p1 = pHead.next 
        pHead.next = p2
        //后移
        p2 = pHead
        pHead = p1
    }
    return p2
}
module.exports = {
    ReverseList : ReverseList
};