recursion program in java

Recursion in Java 1. Concept 定义一个方法时，出现本方法调用本方法的过程，称之为递归2. Features 必然有一个边界条件 使用递归代码往往更简洁，可读性强3. When to use recursionn的阶乘和n的累加定义 f(n) =1 f(n)=f(n)*f(n-1)4. Comparison of common implementations and recursive implementations普通实现 //计算5的阶乘 public class Demo { public static void main(String[] args) { int sum = 1; for (int i =5; i >=1; i--) { sum *= i;

Previously, I tried to solve the problem of jiugong Ge using recursive methods, prompting stack overflow. I'm curious about how many levels of recursion can Java be implemented, and what factors are related to it? Today I did a boring test. I wrote a method. Public void rec1num (int I){System. Out. println ("this is" + I + "recursion ");Rec1num (I + 1

For the file operation to actually look at the next JDK's file class related APIs, the deletion of the folder is primarily a recursive, the reference code is as follows:01.public void Delfolder (String filePath) { . . File Folder = new file (FilePath); if (!folder.isdirectory ()) { . Folder.Delete (); }else if (folder.isdirectory ()) { . String [] filelists = Folder.list (); . for (int i=0;i Delfolder (FilePath

Package Com.readfile;import Java.io.file;public class Getallfiles {public static void main (string[] args) {//path Here write a path into string path= "F:\\QQ document";//Call Method GetFiles (path);} /** * Recursively gets all files, folders under a path, and outputs */public static void GetFiles (String path) {File File = new file (path);//If the path is a folder if (file.i Sdirectory ()) {//Get all Files under path file[] files = file.listfiles (); for (int i = 0; i

: Suppose that a newborn bunny can grow into a big rabbit in one months, and a couple of rabbits in one months, and a couple of bunnies every month, and no death in a year, Q: How many pairs of rabbits do they breed in a year, a pair of newborn rabbits? 1 1 2 3 5 8 13 The first month a pair of bunnies 1 The second month a pair of big rabbits 1 The third month a pair of big rabbits gave birth to a small rabbit 2 The fourth month a pair of big rabbits gave birth to a pair o

Using recursion to delete a non-empty directoryCreation of the Directory: File.makdir ();Deletion of empty directories: File.delete ();Example I, Packagefile;ImportJava.io.File; Public classFiletext { Public Static voidMain (string[] args) {Show (NewFile ("d:/999")); } Public Static voidShow (file file) {if(File.isdirectory ()) {file[] f=File.listfiles (); for(File name:f) {if(Name.isfile ()) {name.delete (); }show (nam

The most recent tool for working with database-guided data is to copy the official line's project to the test environment before the iteration, and perform the upgrade to see if the functionality is complete.So it involves reading the data on the JDBC page and then storing it in the test environment database. Recursion is used where paging is handled.Tools are delivered to test colleagues, most projects can be copied successfully, but some of the larg

); ///stitching the child node's JSON string public string toString () {string result = ' ['; for (Iterator it = List.iterator (); It.hasnext ();) {result = = ((Node) It.next ()). ToString (); result = = ","; result = result.substring (0, Result.length ()-1); result = = "]"; return result; //child node sort public void SortChildren () {//sorting the nodes of this layer//can be passed into a different comparator based on the different sorting properties, where the ID comparator collection

Java programming example of recursive and non-recursive code with two distributions, two Recursion The main content of this article is recursive and non-Recursive Implementation of the binary distribution of Java programming. Source: Exercise 27: return (1.1-p) * binomial (N-1, k, p) + p * binomial (N-1, k-1, k-1, p );How does the recursive formula calculate the

http://blog.csdn.net/sdj222555/article/details/12453629This recursion can be said to be very ingenious.import java.util.*;import java.io.*;import java.math.*;p ublic class Main{ Static biginteger[] g=new biginteger[60];static biginteger[] f=new biginteger[60];static biginteger[] Pow_2=new Biginteger[2510];static long[][] c=new long[60][60];p ublic static void Main (string[] argc) {c[0][0]=1l; for (int i=1;i

PackageCom.swift; Public classDigui_return { Public Static voidMain (string[] args) {/** Recursive algorithm question 2 the first 1 person 10, 2nd than the 1th People's Congress 2 years old, in turn recursive, please use recursion to calculate how big the 8th person? */ intnum = 8; System.out.println ("The 8th person's age is" +Old (num)); } Public Static intOldintnum) { if(num = = 1) { return10; } Else { return

party, Python is used to), get the following code public class Recursion {public static void Main (String args[]) { System.out.print (f (2)); } public static double F (int x) { if (x==0) { return 0; } Else{ return F (x-1) +x/math.pow (4,x);}} The result is: f (2) = 0.375, verify correct3. Calculation of time complexityThe above is an example of the expansion of F (x) =f (x-1) +x/(4**x),Subtract f (x) by 4, so that the x

Recursion in the ordinary development process is not used too much, but as a classical algorithm, we must also understand that recursion in the process of use must have a recursive end conditions, otherwise there will be a Java memory overflow, resulting in the entire system crashes. The following recursive algorithm is used to calculate the cumulative sum of the

removal of contents with contentSuppose there is a demo folder under the project path with some folders and some files, please use recursive thinking to implement.package 递归.作业;import java.io.File;public class FileDiGui2 { public static void main(String[] args) { // 封装File对象 File demo = new File("demo"); // 调用递归删除方法 deleteFile(demo); } // 方法递归:删除 public static void deleteFile(File demo) { // 获取该文件夹下的文件或文件夹路径名数组 File[]

This is a school Java lesson of an experiment, the title is as follows: programming, according to the specified source and destination location, to complete the specified file or folder (including its subfolders, sub-files) replication.Here is my implementation, using recursion:1 Packagecom.simon.myfinal;2 3 ImportJava.io.File;4 ImportJava.io.FileInputStream;5 ImportJava.io.FileOutputStream;6 ImportJava.io

1 ImportJava.io.File;2 Importjava.text.ParseException;3 ImportJava.text.SimpleDateFormat;4 Importjava.util.Date;5 ImportJava.util.Timer;6 ImportJava.util.TimerTask;7 8 /*9 *: Delete the specified directory at the specified timeTen * Set As a timed task One */ A Public classTimertest { - Public Static voidMain (string[] args)throwsException { -Timer T =NewTimer (); the -String s = "2016-04-09 20:46:59"; -SimpleDateFormat SDF =NewSimpleDateFormat ("Yyyy-mm-dd HH:mm:ss"); -Date d =Sdf.parse

public static void Deldir (File f) {Judge whether it is a directory, not the words skip, delete directly; If it is a directory, clear its contents first.if (F.isdirectory ()) {Get sub File/directoryfile[] Subfiles = F.listfiles ();Traverse the Directoryfor (File subfile:subfiles) {Recursive call to delete the file: If this is an empty directory or file, one recursive can be deleted. If this is a non-empty directory, multipleRecursively empties its contents before deletingDeldir (Subfile);}}Delet

1 Public voidRemoveson (String ID, listdeptlist) {2String hql = "from Dept where parent.id =?";3listclass,Newobject[]{id});4 if(list!=NULL list.size () >0){5 for(Dept d:list) {6 Removeson (D.getid (), deptlist);7 }8 }9Dept Dept = Basedao.get (Dept.class, id);Ten deptlist.remove (dept); One}Ideas:1 the department has N sub-departments 2 There are also n sub-divisions under each sub-department 3 4 Delete 5 ideas: function to determine if I

(flag) + "yuan Invoice" + S + "Zhang"); } } Else { ints = totle/(int) list.get (flag); if(S > (int) {list2.get (flag)) {System.out.println ("Need" + list.get (flag) + "yuan Invoice" + S + "Zhang, currently only" + list2.get (flag) + "Zhang, all use! "); Totle-= (int) list2.get (flag) * (int) list.get (flag); System.out.println (Totle); C (Totle,++flag, list, list2); } Else{totle= Totle% (int) list.get (flag); System.out.println ("Need" + list.get (fl

1 /*2 use recursion to find all subdirectories and sub-files under a directory ("C:\\javaproducts")3 */4 5 ImportJava.util.*;6 ImportJava.io.*;7 8 Public classfilerecursionprintdemo{9 Public Static voidMain (string[] args) {TenlistNewArraylist(); Onepaths = Getallfilepaths (NewFile ("C:\\javaproducts"), paths); A for(String path:paths) { - System.out.println (path); - } the } - - Private StaticListfilepaths) { -fil