LeetCode380 常数时间插入.删除和获取随机元素 题目要求 设计一个支持在平均 时间复杂度 O(1) 下,执行以下操作的数据结构. insert(val):当元素 val 不存在时,向集合中插入该项. remove(val):元素 val 存在时,从集合中移除该项. getRandom:随机返回现有集合中的一项.每个元素应该有相同的概率被返回. 示例 : // 初始化一个空的集合. RandomizedSet randomSet = new RandomizedSet(); // 向集合…

Design a data structure that supports all following operations in averageO(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element from…

class RandomizedSet { public: /** Initialize your data structure here. */ RandomizedSet() { } /** Inserts a value to the set. Returns true if the set did not already contain the specified element. */ bool insert(int val) { if(hash.count(val)) return…

l两周以来,第一次睡了个爽,开心! ================================= leetcode380 https://leetcode.com/problems/insert-delete-getrandom-o1/?tab=Description leetcode381 https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed/ leetcode532 https://lee…

题目: Design a data structure that supports all following operations in averageO(1) time. Note: Duplicate elements are allowed. insert(val): Inserts an item val to the collection. remove(val): Removes an item val from the collection if present. getRand…