摘要：
Given an array of integers A with even length, return true if and only if it is possible to reorder it such that A[2 * i + 1] = 2 * A[2 * i] for every 阅读全文
摘要：
Given a string, find the length of the longest substring T that contains at most k distinct characters. Example 1: Input: s = "eceba", k = 2 Output: 3 阅读全文