摘要：Given an integer array of even length arr, return true if it is possible to reorder arr such that arr[2 * i + 1] = 2 * arr[2 * i] for every 0 <= i < l 阅读全文

摘要：An integer array original is transformed into a doubled array changed by appending twice the value of every element in original, and then randomly shu 阅读全文

摘要：You are given an array nums of non-negative integers. nums is considered special if there exists a number x such that there are exactly x numbers in n 阅读全文