Tag:Ascending order

  • mongodb(2)

    Time:2020-4-4

    MongoDB PS many mongodbs do not have a password. The default mongodb does not have a password $type operator For query typeGet document with Title Value of string type in col collection db.col.find(title: {$type: 2}); Limit and skip methods Limit query specified method > db.ming.find().pretty(); { “_id” : ObjectId(“5b5f6eb7d595bb04cbe14b96”), “ming” : “sdfrf” } { “_id” […]

  • The practical analysis of go language bubbling, selection, insertion and quick sorting

    Time:2020-3-21

    Hello, everyone, I’m xiaotanjun. Today’s share is about the practical analysis of sorting in go language. We share the theory and practice of bubble sorting, selection sorting, insertion sorting and fast sorting of go in practice, hoping to bring some inspiration and experience to you on the way of learning. Sorting can often be seen […]

  • Card group

    Time:2020-3-18

    The length of the minimum group is the integer times of other groups export default (arr) => { //Sort this deck, ascending or descending arr.sort((a, b) => a – b) let min = Number.MAX_SAFE_INTEGER let dst = [] let result = true for (let i = 0, len = arr.length, tmp = []; i < […]

  • Sort arrays by parity

    Time:2020-3-11

    export default (arr) => { //Sort ascending arr.sort((a, b) => a – b) //Declare an empty array to store the array after parity sorting let r = [] //Record odd and even Subscripts let odd = 1 let even = 0 //Traversing an array arr.forEach(item => { if (item % 2 === 1) { r[odd] […]

  • The first and last positions of elements in the sorting array

    Time:2020-2-12

    WeChat public address:Drunk front end, for more topics. Title Q:Given an ascending array of integers, nums, and a target value, target. Find the start and end position of the given target value in the array. Your algorithm time complexity must be o (log n) level. Returns [- 1, – 1] if the target value does […]

  • SQL Server Query (select, where, distinct, like query, in, is null, group by and having, order by, as)

    Time:2020-2-7

    Basic query: Example table Example table create table dept( deptno int primary key, dname nvarchar(30), loc nvarchar(30) ); create table emp( empno int primary key, ename nvarchar(30), job nvarchar(30), mrg int, hiredate datetime, sal numeric(10,2), comm numeric(10,2), deptno int foreign key references dept(deptno) ); insert into dept values (10,’ACCOUNTING’,’NEW YORK’); insert into dept values (20,’RESEARCH’,’DALLAS’); […]

  • The way to Python’s advancement (2) dict’s advanced classic

    Time:2020-2-3

    happy new year Hello everyone, today is the second day of the lunar new year. I have no atmosphere for Chinese New Year in foreign countries. I can only write articles and make some contributions to the community. I wish you a happy New Year! In the last issue, I sorted out some advanced uses […]

  • Where / order by / Ggroup by / having

    Time:2020-2-1

    1、Where、Order by、Group by 、having Where object: the basic table or view, from which the eligible elements are selected. The function object of order by is: basic table or view, that is, sorting method, which is divided into ascending (ASC) and descending (DESC). The default sorting is ascending The group by object is a basic table […]

  • Redis must know API

    Time:2020-1-21

    Some nonsense 1. Redis is an open-source, key based storage system with multiple data structures and functions.2. Redis supports persistence, does not lose data after power failure, and asynchronously saves data updates to disk.3. Redis supports string, hash, list, set, ordered set, bitmap, unique count of ultra small memory, and geographic information positioning.4. Redis supports […]

  • JS calculates the number of times the elements appear in the array and implements de duplication

    Time:2020-1-10

    function getCount(arr, rank,ranktype){ var obj = {}, k, arr1 = []; for (var i = 0, len = arr.length; i < len; i++) { k = arr[i]; if (obj[k]) obj[k]++; else obj[k] = 1; } //Save the result {el – ‘element’, count – occurrence times} for (var o in obj) { arr1.push({el: o, count: obj[o]}); […]

  • Several ways to compare sizes

    Time:2019-12-17

    I am a novice, many are excerpts, reference, for notes, in case of need, if there are visitors, light spray.   First, set up an array array; int [] array = New Int [] {1,2,4,3,5,6}; Method 1: direct use (in order: min, Max, average) array.min(); array.max(); array.Average(); This method can be used in array, list, […]

  • Data structure – sorting

    Time:2019-12-13

    —————- sort —————- Bubble sorting idea: “Compare adjacent elements. If the first is bigger than the second, exchange them. Do the same for each pair of adjacent elements, from the first pair at the beginning to the last pair at the end. At this point, the last element should be the maximum number. Repeat the […]