54. 螺旋矩阵 题目 Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. 给个m * n 的矩阵，返回顺时针转一圈的数组。 思路 感觉有点像纯数学问题，每遍历n次，n -

53. 最大子序和 题目 Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. 给个整数数组nums，返回最大子序和。 Follow up: If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach,

没有任何技术或管理上的进展，能够独立地许诺十年内使生产率、可靠性或简洁性获得数量级上的进步。

There is no single development, in either technology or management technique, which by itselfpromises even one order-of-magnitude improvement within a decade in productivity, in eliability,in simplicity.

硬件提高的性能，很快被软件消耗掉了
– 安迪比尔定理

Andy gives, Bill takes away.
– Andy and Bill’s Law

集成电路上可容纳的晶体管数目，约每隔两年便会增加一倍
– 摩尔定律

number of transistors on a given chip can be doubled every two years
– Moore’s Law

本章的主要身体力行的传授了制作一份文档的细节；流程图的心得；以及探讨了自文档化。

51. N 皇后

题目

The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.
N后问题是： n 皇后在 n x n的棋盘上，且两两不能攻击。
Given an integer n, return all distinct solutions to the n-queens puzzle.
给一个整数， 返回所有解法。
Each solution contains a distinct board configuration of the n-queens' placement, where ‘Q’ and ‘.’ both indicate a queen and an empty space respectively.
解里Q代表皇后，.代表空位

本章严肃的讨论了 里程碑 ，并推荐了一种工具 —— PERT

项目是怎样延迟了整整一年的时间？…一次一天。
How does a project get to be a year late? … One day at a time.

此章是从全局视角出发，讲了不少防控bug、debug方面的思路，但由于对debug的应对上已经有些年代了，我认为不太适用于当下，故不赘述。 bug

49. 字母异位词分组

题目

Given an array of strings strs, group the anagrams together. You can return the answer in any order.
给个字符串数组，返回一个“字谜”集合，顺序无所谓。
An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.
字谜的意思是 —— 包含一样的字母但顺序不一样的词，通常每个字母只出现一次

说白了是 字母的 可重复 组合

PS:

1 <= strs.length <= 104
0 <= strs[i].length <= 100
strs[i] consists of lower-case English letters.
英文字典序

巧匠因为他的工具而出名。

• 谚语

A good workman is known by his tools.

• PROVERB

不变只是愿望，变化才是永恒。
SWIFT

普遍的做法是，选择一种方法，试试看；如果失败了，没关系，再试试别的。不管怎么样，重要的是先去尝试。

• 富兰克林 D. 罗斯福

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There is nothing in this world constant but inconstancy.
SWIFT

It is common sense to take a method and try it. If it fails, admit it frankly and try another. Butabove all, try something.

• FRANKLIN D. ROOSEVELT