swift installation skills: how to use map to generate arrays and write 2 lines less code than for (with demo code)

Let's start with the conclusion: map uses 3 lines of code to solve the problem of 5 lines of code in the for loop, which is equivalent to a 40% increase in efficiency You can't learn without (I said) If you don't use it, you won't be able to use it Because you don't know the usage scenario, you can't use it because you haven't learned it ...

Added by MilesStandish on Fri, 14 Jan 2022 02:57:58 +0200

JavaScript: detailed explanation of data types

There are two data types in ECMAScript: basic data type and reference data type. Basic data type Basic data types are also called simple data types, which are Undefined, Null, Boolean, Number, String and Symbol. The basic data type is characterized by a fixed size of space in memory and stored on the stack. 1. Undefined type The undefined type ...

Added by tomfmason on Thu, 13 Jan 2022 17:02:58 +0200

Array simulated queue and the implementation of simulated ring queue

Queue is a first in first out ordered list, which can be realized by array or linked list (for example, Bank Queuing System) prerequisite: maxSize: queue capacity (length of array) arr: array of simulated queues front: points to the previous element of the queue header element, with an initial value of - 1 rear: refers to the element at th ...

Added by CPInteract on Sun, 09 Jan 2022 16:28:55 +0200

Java 2D array

Two dimensional array quick get start Please output the following graphics with a two-dimensional array 0 0 0 0 0 0 0 0 1 0 0 0 0 2 0 3 0 0 0 0 0 0 0 0 The code is as follows: package ArrayList_Practice; public class TwoDimensionalArray01 { public static void main(String[] args) { int arr[][] = {{0,0,0,0,0,0},{0,0,1,0,0,0}, {0,2, ...

Added by mania on Sun, 09 Jan 2022 16:21:29 +0200

java data structure, a case takes you to simulate queues with arrays, ring queues!

queue Queue is a sequential list, which can be implemented by array (sequential storage) or linked list (linked storage).Follow the principle of first in, first out. That is, the data stored in the queue should be taken out first. After the deposit, it shall be taken out. Simulating queues using arrays The queue itself has a seque ...

Added by TexasOutdoors on Wed, 29 Dec 2021 02:18:05 +0200

LeetCode array of question brushing records

In order from simple to difficult, break through the hurdles in turn (the title number is the serial number of leetcode) Main JAVA Source: https://leetcode-cn.com/ catalogue 1. Sum of two numbers (1) - hash table lookup 2. Delete duplicates in the ordered array (26) -- double pointers 3. Remove element (27) - Optimization of double pointe ...

Added by klycette on Mon, 27 Dec 2021 21:28:02 +0200

LeetCode 498. Diagonal traversal [c++/java detailed puzzle]

1. Title Given a matrix with M x N elements (M rows, N columns), return all the elements in the matrix in the order of diagonal traversal, as shown in the following figure. Example: input: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ] output: [1,2,4,7,5,3,6,8,9] Explain: The total number of elements in a given matrix does not exce ...

Added by hurricane on Sat, 25 Dec 2021 19:12:23 +0200

Six methods of array de duplication have also come!

The array object de duplication is completed. Let's look at the array de duplication. 1, The first method Use indexOf() and push() for array de duplication. The indexOf() method returns the first occurrence of a specified string value in the string. If no matching string is found, - 1 is returned. Note: the indexOf() method is case sens ...

Added by slashpine on Sat, 25 Dec 2021 03:49:40 +0200

Java programming exercise Day08

Java programming exercise Day08 Check box control array Example description Check box control is often used in GUI program interface design. For example, many options can be added to the user's favorite program interface. If these options are entered through the GUI interface designer, it is very time-consuming, and the generated code ...

Added by afatkidrunnin on Wed, 22 Dec 2021 06:42:54 +0200

Java data structure Lecture 2 - array / linked list

Common data structures and algorithm implementation (sorting / searching / array / linked list / stack / queue / tree / recursion / massive data processing / graph / bitmap / Java data structure) As the basic skills of programmers, data structures and algorithms must be studied steadily. The bottom layer of our common framework is all kinds ...

Added by packland on Tue, 21 Dec 2021 19:17:02 +0200