LeetCode Walkthrough – Second half of July 2019 (100 walkthrough questions)

Create by jsliang on 2019-07-30 16:15:37

Recently revised in 2019-07-30 16:57:18

In the second half of July, 45 questions were answered, and 100 questions have been answered so far.

A directory

What’s the difference between a free front end and a salted fish

The preface

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Since May 16th of 2019-05-16, Jsliang will do one or more LeetCode problems every day, and record the solution ideas into an article, and post it to GitHub and wechat public account.

• Screenshot of wechat official account record:

• GitHub Record screenshot:

The current arrangement of this LeetCode &&& algorithm and data structure:

1. 【 do 】2019/08/15The former. LeetCode Easy Puzzles – Complete 100 easy LeetCode puzzles.
2. [Ready to start]2019/08/01 – 2019/09/01. Delve into algorithms and data structures.
3. Not yet. LeetCode Medium Difficulty Problems – Complete 50 Medium LeetCode problems.
4. Not yet. Further delve into algorithms and data structures.
5. Not yet. LeetCode Difficult Problems – Complete 20 difficult LeetCode problems.
6. Not yet. Improve algorithms and data structures.

What Jsliang has learned in LeetCode so far:

• JS basics: ES5, ES6, and other apis, and their applications…
• Problem-solving thinking: encounter difficulties, will first analyze the cracking method of this problem, and then further explain the optimization ideas…
• Algorithms and data structures: dual Pointers, dynamic programming, linked lists, binary trees…

So, if you like Jsliang, want to improve the understanding and use of native JS API, familiar with the algorithm and data structure, you can follow jsliang official account and GitHub:

• The public no. :

• GitHub: Jsliang document library

Three summary

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Compare jsliang’s LeetCode summary for June and mid-July:

• LeetCode June summary
• LeetCode mid July summary

LeetCode changed from 1,114 questions to 1,134 questions, an increase of 20 questions.

Jsliang in LeetCode has changed from 55 questions to 100 questions, adding 45 questions to solve.

Jsliang has added several basic JavaScript articles to the basic knowledge of JavaScript.

3.1 LeetCode has been outlined

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Jsliang has mastered 100 leetcodes so far.

If you come up with some excellent solutions in the process of LeetCode, you are welcome to submit to Issue, or directly leave a message in jsliang’s booklet, or drag it to the bottom of the article and add jsliang’s wechat account, etc. :

• Document. Jsliang. Top.

Jsliang will add the GitHub nickname and address of the friend who provided the solution to the question according to the content of the comment.

So, without further ado, here’s the list:

• 001 – Double sum
• 007 – reverse-integer stocking
• 009 – Palindrome -number of bookmarks
• 013 – Roman to integer bookmarking
• 014 – Longest common-prefix
• 020 – valid parentheses
• 021 – Merge two merge-two-sorted-lists
• 026 – Delete duplicate items from the sorted array (remove-duplicates-from-sorted-array)
• 027 – Remove remove-element tags
• 028 – Enable strStr (implement- strStr)
• 029 – Search for search-insert-position in your ➤
• 038 – count-and-say bookmarking
• 053 – Maximum subarray and ➤
• 058 – Length of last word (length-of-last word
• 066 – Plus -one bookmark
• 067 – Add -binary bookmarking
• ➤ The square root of 069-x
• 070 – Climbing -stairs
• 083 – Delete duplicate elements from the sort list (remove-duplicates-from-sorted-list)
• 088 – Merge two merge-sorted arrays
• 100 – Same tree
• 101-symmetric binary tree
• 104-Maximum depth of binary tree
• 107 – Binary tree-level-order-traversal-ii searchable foreground
• 108 – Convert ordered arrays to convert-sorted array-to-binary search-tree
• Come up in balanced-binary-tree
• Configure the minimum-depth-of-binary tree
• 112 – Path-sum ➤
• 118 – Open TAB in pascical-Triangle
• 119-Open ➤ In Pascical-triangle-II
• 121-Best time to buy and sell stocks
• 122 – Best time to buy and sell stocks II
• 125-Verify valid-palindrome stocking
• 136 – Single-number bookmarks that appear only once
• 141-Link -list-cycle ➤
• ✔ Min-stack
• 160-intersection-of-two-linked-lists
• Come up in (two-sum-iI-input-array-is-sorted) bookmark
• 168 – Excel column name (Excel -sheet-column-title
• ➤ For majority-element
• 171-excel bookmark (Excel sheet-column-number
• 172 – Zero (factorial trailing-zeroes) trailing
• Searched-array searchable TAB
• 190 – Reverse -bit ➤
• ✔ 191-number of 1-bits
• Come and join the family
• 202 – Happy number
• 203 – Remove remove-linked-list-elements from your organization
• ✔ Count -primes
• 205 – Isomorphic strings
• 206 – Reverse linked-list ➤
• 217 – There is a double element in it
• 219 – There is a double element II (contains- duplicate-II) in it
• 225-Enable (implement-stack-using-queues) in queues
• Turn your invert-binary-tree TAB
• Come up in 231-2 power
• Configure your ➤ in implement-queue-using stacks
• 234 – Palindrome-linked-list ➤
• Lowest-common-ancestor-of-a-binary-searching-tree ➤
• 237 – Delete delete-node-in-a-linked-list nodes
• 242 – Valid -anagram right ➤
• ✔ All binary-tree-paths in the 257-binary tree
• 258 – Add -digits
• 263-ugly number
• 268 – Missing number of bookmarks
• 278 – First wrong version
• 283 – Move-zeroes ✔
• 290 – Word-pattern bookmarking
• ✔ Nim game
• 303 – Range-sum -query-immutable array for regions and retrievals
• Come up in 326-3 power of three
• ➤ Power of 342-4
• ✔ Reverse-string
• Come up in reverse vowels- a-string
• 349 – Intersection of two arrays
• 350 – Intersection of two-arrays-II ➤
• 367-Valid perfect square ✔
• (1) integers
• Come up in front of your ransom notes
• ✔ 387-First unique character-in-a-string in a string
• 389 – Search for find-the-difference
• 400 – NTH digit (nTH-digit) ✔
• 401-binary-watch stocking
• 404 – Sum -of-left-leaves
• 405-numbers can be converted to convert-a-number-to-hexadecimal
• Roll in the longest palindrome
• 412-Fizzbuzz (Fizz-buzz) bookmark
• 414 – Third -maximum-number
• 415 – Add -strings
• ➤ N-ary -tree-level-order-traversal in 429-N fork trees
• 434 – Number of words in the string (number-of-sales-in-a-string)
• 437 – Path-sum-III ✔
• 438 – Find all alphabetical ➤ in the string (find-all-Anagrams-in-a-string
• Arranging – Coins in blue stocking
• Return to foreground (string-compression)
• 447 – Number of boomerangs in your head
• Box-sizing: border-box! Important; color: RGB (50, 50, 50); font-size: 13font-kerning; white-space: normal; white-space: normal
• 453 – Minimum movements-to-equal array-elements in the foreground
• 455 – Bookmark your bookmarks
• 459 – Repeat string (repeated-substring-pattern) bookmark

3.2 the Function & Object

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In the process of brushing LeetCode, I came into contact with some methods and objects of native JS. I recommend you to eat them with the solution of LeetCode. After all:

• Useless knowledge points are all rubbish in the brain

Method the Function –

• Methods – charCodeAt ()
• Method, the filter ()
• Methods – the forEach ()
• Methods – fromCharCode ()
• Method indexOf ()
• Method, the join ()
• Methods – the map ()
• Methods – padStart ()
• Method, the parseInt ()
• Methods – pop ()
• Methods – push ()
• Methods to reduce ()
• Method, the reverse ()
• Methods – the shift ()
• Method, the slice ()
• Methods – the sort ()
• Methods – splice ()
• Method, the split ()
• Method the substring ()
• Methods – toLocaleLowerCase ()
• Methods – the toString ()
• Methods – unshift ()

Object the Object –

• Objects to the Map
• Object – Math
• Object – Number
• Object – the RegExp
• Object – Set
• Object – String

Four summarizes

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The increase of knowledge does not happen overnight. Before today, Jsliang had sketched a simple and difficult LeetCode every morning from 7:30 to 9:00, and recorded his thoughts in the form of articles.

At present, the simple difficulty strategy has reached 100 questions, so jsliang will adjust itself to brush algorithms and data structures, while tackling the medium difficulty problems.

As for the later advanced difficulty, I will step by step to attack, interested friends can continue to follow my GitHub, Nuggets, public account:

• GitHub – Jsliang document library
• Denver – jsliang

Finally, Jsliang will absorb the excellent articles of some friends around him and learn to toss with them.

If you feel your article is also good, welcome to share:

Front-end interview daily 3+1, to interview questions to drive learning, insist on learning and thinking every day, a little progress every day!

• Vue 248+ points (interview questions
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• Front-end interview 3+1 per day (weekly summary 2019.07.28)

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