剑指 Offer II 022. 链表中环的入口节点

2022-05-08 107 阅读1分钟

var detectCycle = function (head) {
    var node = head
    var map = new Map()
    while (node) {
        map.set(node, true)
        node = node.next
        if (map.has(node)) return node
    }
    return null
};