online programming practice

;publicclassmain{ publicstaticvoidmain (String[]args) { scannerin=newscanner (system.in); stringnum=in.next ();int Result=0;while (result!=6174) { intleft=0; intright=0; char[]temp=creat (num); char[]l=newchar[4]; arrays.sort (temp); for (inti=3;i>=0;i--) { left=left*10+temp[i]-' 0 '; right=right*10+temp[3-i]-' 0 '; l[i]=temp[3-i] ;} if (left==right) { system.out.println (Newstring (L) + "-" +new String (temp) + "=0000"); return;} result=left-right; system.out.println (Newstring (L) + "-" +newst

of the code: so that the single process can handle the multi-client connection, for the single-core CPU, Single process using select processing connection and listening sockets its efficiency is not necessarily worse than multi-process/multithreading performance; **/struct sockaddr_in clientaddr; Socklen_t Addrlen; int maxfd = LISTENFD; Fd_set RSet; Fd_set Allset; Fd_zero (rset); Fd_zero (allset); Fd_set (LISTENFD, allset); Used to save the connected client socket int

This is a creation in Article, where the information may have evolved or changed. In the previous article Go Socket programming Practice: TCP Server and client implementation, we implemented an echo server, and also implemented a client to access the server.This article explains how to implement a UDP server and client.The protocol we're using this time is RFC 868,This protocol provides a site-independent,

::getaddr () {if (IsValid ()) {return Inet_ntoa (M_ADDRESS.SIN_ADDR); } return std::string ();} int SOCKET::GETPORT () const{if (IsValid ()) {return ntohs (m_address.sin_port); } return-1;} static ssize_t readn (int fd, void *buf, size_t count) {size_t nleft = count; ssize_t nread = 0; Char *ptr = Static_castSocketException.h#ifndef socketexception_h_included#define socketexception_h_included//Exception handling Class (the next section will use ...) Class Socketexception{public: sock

SendBuf; while (Getline (CIN,SENDBUF)) { if (!clientsocket.send (clientsocket,sendbuf)) { Err_exit (" Send Error "); } Sendbuf.clear (); if (!clientsocket.receive (clientsocket,sendbuf)) { err_exit ("Receive error"); } cout Attached -commen.h#ifndef comment_h_included#define comment_h_included#include "Socket.h" #include Attached -makefileCC = g++ Cppflags =-wall-g-pthreadbin = Server Clientsources = $ (bin.=.cp

application Application5, tells the Application5 data arrives, needs to deal with!Illustration 3: A typical "push mode"Illustration 4: One of the most efficient modes , the upper-level application Application5 has the ability to process asynchronously (with the support of the Linux kernel , can also support IO communication while other tasks are being handled .What does asynchronous I/O mean?The upper-level application Application5, while doing other tasks, can also receive data (accept asynch

Duplicate phone numberLook for a duplicate phone number in a file, all uppercase and lowercase letters are mapped to numbers according to the cell phone nine, the remaining characters are not considered, the duplicate number is restored after the output to the interface file, the number is less than 12 bits.#include BYTE Stream parsingFor a char byte array, specify the position, specify the length, and parse out the number.#include "OJ.h" #include English Melody ContestGet the score from the inp

L2-1. Emergency response time limit of MSMemory Limit 65536 KBCode length limit 8000 BProcedures for the award of questions StandardAuthor ChenAs the head of a city's emergency rescue team, you have a special national map. The map shows a number of scattered cities and some quick roads connecting the city. The number of rescue teams in each city and the length of each fast road connecting two cities are marked on the map. When other cities have an emergency call for you, your task is to lead you

)). Start (); } }} class userloginthread implements Runnable{ PrivateSocket s; Userloginthread (Socket s) { This. s=s; } Public voidRun () {Try{BufferedReader burin=NewBufferedReader (NewInputStreamReader (S.getinputstream ())); for(intI=0;i3; i++) {String user=burin.readline (); System.out.println ("username sent to:"+user);if(user==NULL) {System.out.println ("is empty"+user); Break; } BufferedReader bur=NewBufferedReader (NewFileReader ("User.txt")); String line=NULL;Booleanflag=false; w

Write a Java program that calculates the circumference length and area of the RADIUS 3.0 and outputs the results.Note: The system class math is in the Java.lang packet, and pi π can be obtained by the static attribute pi of the math class, which is defined as "public static final double PI = 3.14159265358979323846;".1 PackageCom.hanqi;2 3 Importjava.lang.*;4 5 //Write a Java program that calculates the circumference length and area of the RADIUS 3.0 and outputs the results. 6 7 //Note: The Syst

Pku c ++ Programming Practice Study Notes 4 Operator Overloading Chapter 4 Operator Overloading4.1 basic concepts of Operator Overloading 1. Operators 2. Custom Data Types and Operator Overloading C ++ provides data abstraction means: You can define your own data types-classes.? Call a member function of a class-> operate on its objects Class member functions-> inconvenient to operate on objects? In mathema

Chapter 5 Programming Practice Analysis in the first quarter of Java 5-1 basic writing 　　 Automatic completion shortcut: alt +/ 5-2 Input and Output Use the score tool class to obtain user-input score Information The category class is located in the java. util package. You need to import this package when using it. Steps: 1. Import java. util. Vendor 　　 2. Create a producer object 　　 3. Recei

Java Programming Practice: Determine whether the Java file name is correct, determine whether the mailbox format is correct, and count the number of times a character in a specified string appears1. Determine whether the Java file name is correct and whether the mailbox format is correct Function: determines whether the Java file name is correct and whether the mailbox format is correct. Valid file names sh

1, reverse a string of strings output, such as "ABCD" into "DCBA"str1= "ABCD" Print Str1[::-1]2, judge whether it is a palindrome--to determine whether the user input string is a palindrome. Palindrome refers to both positive and negative spellings are the same words, such as "racecar".while (1): input_str = raw_input (' Please input your string: ') if input_str== "quit": print "Bye" break elif input_str==input_str[::-1]: print "Your input is Huiwen" else:

Linux inter-process communication (IPC) Programming Practice (9) System V semaphores-A toolset for encapsulating a semaphores operationMain API # include # Include # Include Int semget (key_t key, int nsems, int semflg );Int semctl (int semid, int semnum, int cmd,...); int semop (int semid, struct sembuf * sops, unsigned nsops ); SemgetInt semget (key_t key, int nsems, int semflg);/** Example 1:

Win Programming Practice (4) [c ++]-multi-dimensional array pointer // Leleapplication1.cpp: defines the entry point of the console application. // # Include "stdafx. h" # Include Using std: cout; Using std: endl; Using std: cin; All content of this blog is original, if reproduced please indicate the source http://blog.csdn.net/myhaspl/ Int main () { Char temp; Int x [2] [4]; For (int I = 0; I For

1-function Dnastr (s) { //ps: No AC, see bug Please indicate if (s.length>=1s.length2-function Issame (str) { //determines if the string var begin = 0 var end = Str.length/2 while (End 3-PS: See the bug to help point out, XieJS Programming Little Practice 2の Cattle

This is my note on the Java course of learning web. The original video link is: http://www.imooc.com/learn/855-1 Basic NotationSelf-complementary shortcut keys: ALT +/5-2 input and outputUse the Scanner tool class to get user-entered score informationThe scanner class is located in the Java.util package and needs to be imported when using the packagesteps:1. Import Java.util.Scanner2. Create a Scanner object3. Receive and save user-entered valuesdifference between System.out.println () and Syste

always holds the correct lock when visiting the data.A closed mechanism is easier to construct a thread-safe class, because when the state of the enclosing class is parsed, the entire program is not required to examine the thread security of the class.Even if the closure can guarantee that all processing within the object is readily available, it is also important to note that when the object is advertised, it is possible to fail, such as hashset-only one variable in the sample object ensures t

not be deleted, not directly assigned to modify!Dimensions = (200,50)print (dimensions[0])print (dimensions[1])# Running Results 20050You can use a for loop to traverse the entire tupleAlthough you cannot modify the elements of a tuple, you can assign values to the variables of the storage tuple.Therefore, you can only redefine the entire tuple if you want to modify it. Dimensions = (200,50) for in dimensions: print= (100,120 ) for in dimensions: print (dimension)# Running Results 200