题解 | #链表中环的入口结点#

/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function EntryNodeOfLoop(pHead)
{
    const listset = new Set()
    if(pHead===null) return null
    let p = pHead
    while(p!==null){
       if(listset.has(p)) return p
       else{
        listset.add(p)
        p = p.next
       }
    }
    return null
}
module.exports = {
    EntryNodeOfLoop : EntryNodeOfLoop
};