题解 | #链表中环的入口结点#

/*function ListNode(x){
    this.val = x;
    this.next = null;
}*/
function EntryNodeOfLoop(pHead)
{
    // write code here
    const set = new Set();
    let cur = pHead;
    while(cur){
        if(set.has(cur)){
            return cur
        }
        set.add(cur)
        cur = cur.next;
    }
    return null;
}
module.exports = {
    EntryNodeOfLoop : EntryNodeOfLoop
};

解题思路：判断节点是否重复出现，出现的第一个便是入口