2018-09-01

Leetcode 经验

String

遇到String 的题目，首先的想法是用指针i, j的方式做题

两种视角

Recursion：从顶端找底端

用Recursion的方式，如果会有重复的部分，新建一个Helper，存储所有见过的计算结果

EXAMPLE：62. Unique Paths

class Solution:
    def uniquePaths(self, m, n):
        """
        :type m: int
        :type n: int
        :rtype: int
        """
        def helper(m,n,seen):
            if (m,n) in seen: return seen[(m,n)]

            if (m == 2 and n == 1) or (n==2 and m==1) or (m==1 and n ==1):
                return 1

            count = 0
            if m-1 >= 1:
                count += helper(m-1,n,seen)
                seen[(m-1,n)] = count
            if n-1 >=1:
                temp = helper(m, n-1, seen)
                seen[(m,n-1)] = temp
                count += temp

            return count

        return helper(m,n,{})

Store in a list：从底端到顶端

如果从0/1开始，都要遍历，可以从底端到顶端

用list，存储从小到大的结果

返回值为最后的最大值

EXAMPLE：62. Unique Paths

def uniquePaths2(self, m, n):
    """
    :type m: int
    :type n: int
    :rtype: int
    """
    
    """
    坐标系
    Finish： A[0,0]
    Start： A[m-1,n-1]
    """

    # 预先设定其他的都是[1],那么A[i][0], A[0][j],就不需要进行遍历
    A = [[1] * n] * m

    # 直接从A[1][1]开始
    for i in range(1, m):
        for j in range(1, n):
            A[i][j] = A[i - 1][j] + A[i][j - 1]

    return A[m - 1][n - 1]

Palindromic Substring

EX: LC5: Longest Palindromic Substring

1
2
3

Input: "babad"
Output: "bab"
Note: "aba" is also a valid answer.

Select a center, like “a”, “aa”, “aaa”
Spread the center
Use Middle to remeber the center, and use i, j to spread it.

2018-07-30

Web►Back-end►Django

Establish a django project

After Django Installed

1. Activate the virtual environment

1	$ source activate myDjangoEnv

2. Init the project

1	$ django-admin startproject first_project

Default Files

__init__.py
This is a blank Python script that due to its special name let’s Python know that this directory can be treated as a package
settings.py
This is where you will store all your project settings
urls.py
This is a Python script that will store all the URL patterns for your project. Basically the different pages of your web application.
wsgi.py
This is a Python script that acts as the Web Server Gateway Interface. It will later on help us deploy our web app to production
manage.py
This is a Python script that we will use a lot. It will be associates with many commands as we build our web app!

3. Run server to test

1	$ python manage.py runserver

Use the given url, you can see it.

3. Start Application

1	$ python manage.py startapp first_app

2018-07-24

python

Set Max and Min in Python

1 2	max = float('inf') min = float('-inf')

2018-07-22

Web►Front-end

Build a html page

1. Build Connections

a. Establish your `html` files

b. link the `CSS` files and the `js` files

b.1 directly use `bootstrap`, but still need to link

https://getbootstrap.com/docs/4.1/getting-started/introduction/

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.2/css/bootstrap.min.css" integrity="sha384-Smlep5jCw/wG7hdkwQ/Z5nLIefveQRIY9nfy6xoR1uRYBtpZgI6339F5dgvm/e9B" crossorigin="anonymous">

b.2 link `CSS files`

1	<link rel="stylesheet" href="/css/master.css">

b.3 link `js` files

1	<script src="MyScript.js"></script>

2018-07-13

Web►Front-end

HTML Basics

学习笔记：

https://github.com/yukiii-zhong/Udemy_Django_Course/tree/master/HTML_LEVEL_ONE

https://github.com/yukiii-zhong/Udemy_Django_Course/tree/master/HTML_LEVEL_TWO

1. Comment

1	<!-- This is a comment -->

Shortcut: COMMAND+/

2. 基本格式

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    <title>This is the Title!</title>
  </head>
  <body>
    <!-- This is a comment -->

  </body>
</html>

<head> Part don’t actually show in the page, it’s just the head

<body> it’s the real shown part.

3. 查看效果（In Atom）

Right Click the htmlfile
Select copy full path
Run the copied path in the Browser

4. 查询资源

W3school,
Mozilla - More Detailed

2018-07-13

Uncategorized

Build Flask Environment

Use Pycharm

go to preference
Search Project Interpreter
+ Flask Package

2018-07-12

Shell Command

Forking Repo

1. Fork the Repo

1.1 fork the Repo to your own.

1.2 Clone it from your own.

1	$ git clone https://github.com/yukiii-zhong/lighthouse.git

2. Filtering Collaborator’s Commits

2.1 Group By Commit Author

a. common

1	$ git shortlog

b. only see number of commits

1	$ git shortlog -s -n

-s –> just show the number of commits

-n –> sort them numerically

c. only show specific author commits

1	$ git shortlog --author=Paul

2.2 Filter Commits By Search

1 2	$ git log --grep=bug $ git log --grep bug

if you were to run git log --grep "fort", then Git will display only the commits that have the character f followed by the character o followed by r followed by t.

2018-07-11

Leetcode

186. Reverse Words in a String II

思路

We need to reverse the string word by word

Reverse the whole string
Reverse back each word in the string.

2018-07-11

Leetcode

93. Restore IP Addresses

前提规则

IP地址由32位二进制数组成，为便于使用，常以XXX.XXX.XXX.XXX形式表现，每组XXX代表小于或等于255的10进制数。所以说IP地址总共有四段，每一段可能有一位，两位或者三位，范围是[0, 255]
当只有一位时，0可以成某一段，如果有两位或三位时，像 00， 01， 001， 011， 000等都是不合法的

思路

Split String according to length combinations
Judge whether each split is valid
Return valid res.

2018-07-07

Shell Command

Git: Working with Remotes

1	$ git remote

PartA. Add A Remote Repository

1. Create A Simple Project

Create a Project directory
git init to turn it into a Git repository
Create a README.md file
Create other files

2. Hosting on GitHub

Creat the repo on GitHub

3. Manage the Repository: `git remote`

1	$ git remote

It’s possible to have links to multiple different remote repositories.
A shortname is the name that’s used to refer to a remote repository’s location. Typically the location is a URL, but it could be a file path on the same computer.
git remote add is used to add a connection to a new remote repository.
git remote -v is used to see the details about a connection to a remote.

PartB. Push Changes To A Remote

1. Check the commits

1	$ git log --oneline --graph --all

2. Push the commits

$ git push <remote-shortname> <branch>

# EX:
$ git push origin master

PartC: Pulling Changes From A Remote

1	$ git pull origin master

When git pull is run, the following things happen:

the commit(s) on the remote branch are copied to the local repository
the local tracking branch (origin/master) is moved to point to the most recent commit
the local tracking branch (origin/master) is merged into the local branch (master)

PartD: Pull vs Fetch

1	$ git fetch origin master

fetch the changes, but not merge them