摘要：
Given an integer array nums, return the number of range sums that lie in [lower, upper] inclusive. Range sum S(i, j) is defined as the sum of the elem 阅读全文
摘要：
Given a non-empty array of integers, return the k most frequent elements. For example, Given [1,1,1,2,2,3] and k = 2, return [1,2]. Note: You may assu 阅读全文
摘要：
Design a Tic-tac-toe game that is played between two players on a n x n grid. You may assume the following rules: Example: Follow up: Could you do bet 阅读全文