题解 | #判断链表中是否有环#
判断链表中是否有环
http://www.nowcoder.com/practice/650474f313294468a4ded3ce0f7898b9
/*
* function ListNode(x){
* this.val = x;
* this.next = null;
* }
*/
/**
*
* @param head ListNode类
* @return bool布尔型
let set = new WeakSet();
let p = head;
while(p !== null){
if(set.has(p)){
return true;
}else{
set.add(p)
}
p=p.next;
}
return false;
}
module.exports = {
hasCycle : hasCycle
};
* function ListNode(x){
* this.val = x;
* this.next = null;
* }
*/
/**
*
* @param head ListNode类
* @return bool布尔型
*/
//WeakSet用来临时存储链表的节点,如果当前节点weakset中已经存在,说明有环
function hasCycle( head ) {let set = new WeakSet();
let p = head;
while(p !== null){
if(set.has(p)){
return true;
}else{
set.add(p)
}
p=p.next;
}
return false;
}
module.exports = {
hasCycle : hasCycle
};