Brain Dumps

在计算机科学中，最大子数列问题的目标是在数列的一维方向找到一个连续的子数列，使该子数列的和最大。例如，对一个数列 −2, 1, −3, 4, −1, 2, 1, −5, 4，其连续子数列中和最大的是 4, −1, 2, 1, 其和为6。 该问题最初由布朗大学的Ulf Grenander教授于1977年提出，当初他为了展示数字图像中一个简单的最大似然估计模型。不久之后卡内基梅隆大学的Jay Kadane提出了该问题的线性算法。（Bentley 1984）。 Kadane算法[编辑] Kadane算法扫描一次整个数列的所有数值，在每一个扫描点计算以该点数值为结束点的子数列的最大和（正数和）。该子数列有可能为空，或者由两部分组成：以前一个位置为结束点的最大子数列、该位置的数值。可用如下代码表示，这里用到了Python: def max_subarray(A):     max_ending_here = max_so_far = A[0]     for x in A[1:]:         max_ending_here = max(x, max_ending_here + x)         max_so_far = max(max_so_far, max_ending_here)     return max_so_far 该问题的一个变种是：如果数列中含有负数元素，不允许返回长度为零的子数列。该问题可用如下代码解决： def max_subarray(A):     max_ending_here = max_so_far = A[0]     for x in A[1:]:         max_ending_here = max(x, max_ending_here + x)         max_so_far = max(max_so_far, max_ending_here)     return max_so_far 这种算法稍作修改就可以记录最大子数列的起始位置。 Kadane算法时间复杂度为 {\displaystyle {\mathcal {O}}(n)}，空间复杂度为 {\displaystyle {\mathcal {O}}(1)}. 因为该算法用到了“最佳子结构”（以每个位置为终点的最大子数

An All-Hands Meeting is generally an organization wide business meeting in which an executive report is made to employees and stake holders. All-Hands meetings are often held on a regular basis as a means of keeping a large group of people up to date on important events and milestones. All-Hands Meetings can be held in conference rooms, corporate cafeterias, hotel ballrooms and across many time zones and continents. An effective All-Hands Meeting usually begins with an important message and includes some form of question and answer capability. The term "Town Hall" meeting is often used interchangeably with All-Hands meeting however a Town Hall meeting is more question and answer based while All-Hands meetings are generally more focused on conveying a message and making a key presentation. ref: http://www.video-conferencing.com/definition/all-hands-meeting.html