题解 | #反转链表#

/*
 * function ListNode(x){
 *   this.val = x;
 *   this.next = null;
 * }
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
function ReverseList( head ) {
    if(!head || !head.next) return head;
    let pre = null;
    let cur = head;
    let temp = null;
    while(cur){
        temp = cur.next;
        cur.next = pre;
        pre = cur;
        cur = temp;
    }
    return pre;
    // write code here
}
module.exports = {
    ReverseList : ReverseList
};