关于算法:数据结构链表

把数组转成链表

         var head = [1, 2, 3, 4, 5]         function arrayToListNode(arr) {            if (arr.length === 0) return null;            let head = { val: arr[0], next: null }            let pre = head;            for (let i = 1; i < arr.length; i++) {                pre.next = { val: arr[i], next: null }                pre = pre.next                // let node = { val: arr[i], next: null }                // pre.next = node;                // pre = node            }            return head        }        head = arrayToListNode(head)        console.log('head', head)