LeetCode 381. Insert Delete GetRandom O(1) - Duplicates allowed O(1) 时间插入、删除和获取随机元素 - 允许重复(C++/Java)
摘要：
题目： Design a data structure that supports all following operations in averageO(1) time. Note: Duplicate elements are allowed. insert(val): Inserts an 阅读全文