前端生产一个环状链表

function gerLink(len) {
    const head = {};
    let p = head;
    for(let i = 1; i <= len; i++) {
        const cur = {
            val: i
        }
        p.next = cur;
        p = p.next;
    }

    p.next = head.next;

    return head.next;
}

const ll = gerLink(3);

console.log('l::', ll);