019删除倒数第n个节点

code

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} n
 * @return {ListNode}
 */
var removeNthFromEnd = function(head, n) {
    if(head.next === null && n === 1){
        return null;
    }
    let ind_slow = head;
    let ind_fast = head;
    for(let i = 0; i < n; i++){
        ind_fast = ind_fast.next;
    }
    if(ind_fast === null) {
        return head;
    }
    while(ind_fast.next !== null){
        ind_slow = ind_slow.next;
        ind_fast = ind_fast.next;
    }
    ind_slow.next = ind_slow.next.next;
    return head;
};

总结

1. 貌似是一眼快慢指针