题目描述：

LeetCode 634. Find the Derangement of An Array

In combinatorial mathematics, a derangement is a permutation of the elements of a set, such that no element appears in its original position.

There's originally an array consisting of n integers ...

题目描述：

LeetCode 635. Design Log Storage System

You are given several logs that each log contains a unique id and timestamp. Timestamp is a string that has the following format: Year:Month:Day:Hour:Minute:Second, for example, 2017:01 ...

题目描述：

LeetCode 633. Sum of Square Numbers

Given a non-negative integer c, your task is to decide whether there're two integers a and b such that a² + b² = c.

Example 1:

Input: 5
Output: True
Explanation: 1 * 1 ...

LeetCode Weekly Contest 38是LeetCode举办的第四十三场正式周赛，共4道题目，比赛时长1.5小时。

比赛链接：https://leetcode.com/contest/leetcode-weekly-contest-38/

题解列表：

LeetCode 628. Maximum Product of Three Numbers

LeetCode 630. Course Schedule III

LeetCode 629. K Inverse Pairs Array

LeetCode 631. Design Excel Sum Formula

题目描述：

LeetCode 631. Design Excel Sum Formula

Your task is to design the basic function of Excel and implement the function of sum formula. Specifically, you need to implement the following functions:

Excel(int H, char W): This is the ...