#   20202324 2021-2022-1 data structure and object oriented programming experiment 4 report

Course: programming and data structure
Class:   two thousand and twenty-three
Name: Xiao Zhiyu
Student No.: 20202324
Experimental teacher: Wang Zhiqiang
Experiment date: October 28, 2021
Compulsory / elective: compulsory

1, Experimental content

1. Linked list exercise requires the following functions:

• Input some integers through the keyboard to establish a linked list;
  These numbers are the two digits taken out in turn from your student number. Plus today's time.
  For example, your student number is 20172301
  Today's time is October 1, 2018, 16:23:49 seconds
  Numbers are
  20， 17，23，1， 20， 18，10，1，16，23，49
  Print all linked list elements and output the total number of elements.
  In your program, please use a special variable name to record the total number of elements. The variable name is your name. For example, if your name is Zhang San, the variable name is
  int nZhangSan = 0; // Initialize to 0
  After this step, check your program into source code control (git push).

2. Linked list exercises are required to achieve the following functions:

• Implement node insertion, deletion and output operations;
  Continue with your previous program and expand its functions. Every time you finish a new function or write more than 10 lines of new code, check in the code and submit it to the source code server;
  Read a file from disk. The file has two numbers.
  Read the number 1 from the file, insert it into the fifth digit of the linked list, and print all numbers and the total number of elements. Keep the linked list and continue with the following operations.
  Read the number 2 from the file, insert it into position 0 of the linked list, and print all numbers and the total number of elements. Keep the linked list and continue with the following operations.
  Delete the number 1 from the linked list and print the total number of all numbers and elements.

3. Linked list exercises are required to achieve the following functions:

• Use bubble sorting method or selective sorting method to sort the linked list according to the value size;
  If your student number is singular, select bubble sort, otherwise select sort.
  In each round of sorting, print the total number of elements and all elements of the current linked list.
  Continue to expand in the program obtained in (2), and write different functions with the same program file to realize this function. Still use nZhangSan (your name) to represent the total number of elements.

4. Implement experiments (1) and (2) on android

5. Experiment on android platform (3)

2, Experimental process and results

1. Linked list exercise requires the following functions:

• Input some integers through the keyboard to establish a linked list;
  These numbers are the two digits taken from your student number in turn. Add today's time.
  For example, your student number is 20172301
  Today's time is October 1, 2018, 16:23:49 seconds
  Numbers are
  20， 17，23，1， 20， 18，10，1，16，23，49
  Print all linked list elements and output the total number of elements.
  In your program, please use a special variable name to record the total number of elements. The variable name is your name. For example, if your name is Zhang San, then the variable name is
  int nZhangSan = 0; / / initialize to 0
  After this step, check your program into source code control (git push).

Experimental screenshot

 

 

 

 

 

2. Linked list exercises are required to achieve the following functions:

• Implement node insertion, deletion and output operations;
  Continue with your previous program and expand its functions. Every time you finish a new function or write more than 10 lines of new code, check in the code and submit it to the source code server;
  Read a file from disk. The file has two numbers.
  Read the number 1 from the file, insert it into the fifth position of the linked list, and print all numbers and the total number of elements. Keep the linked list and continue the following operation.
  Read the number 2 from the file, insert it into position 0 of the linked list, and print all numbers and the total number of elements. Keep the linked list and continue the following operation.
  Delete the number 1 from the linked list and print the total number of all numbers and elements.

3. Linked list exercises are required to achieve the following functions:

• Use bubble sorting method or selective sorting method to sort the linked list according to the value size
  If your student number is singular, select bubble sort, otherwise select sort.
  In each round of sorting, print the total number of elements and all elements of the current linked list.
  Continue to expand the program obtained in (2) and write different functions with the same program file to realize this function. Still use nZhangSan (your name) to represent the total number of elements.
   
   
  

   

   

  
  

   

Experimental screenshot

 1 public class Chain {
 2     protected int element;
 3     protected Chain next = null;
 4 
 5     public Chain(int element) {
 6         this.element = element;
 7         this.next = next;
 8     }
 9 
10     public int getElement() {
11         return element;
12     }
13 
14     public void setElement(int element) {
15         this.element = element;
16     }
17 
18     public Chain getNext() {
19         return next;
20     }
21 
22     public void setNext(Chain next) {
23         this.next = next;
24     }
25 }

  1 import java.io.*;
  2 import java.util.Scanner;
  3 
  4 public class Chain_2 {
  5     public static Chain head;
  6     public static int nXiaoZhiYv = 0;
  7 
  8     public static void main(String[] args) throws IOException {
  9         Scanner scan=new Scanner(System.in);
 10 
 11         //Enter and create the header first
 12         System.out.println("Enter numbers("+(nXiaoZhiYv + 1)+").Type stop if you want to stop.");
 13         String str = scan.nextLine();
 14         Chain chain0 = new Chain(Integer.parseInt(str));
 15         head = chain0;
 16 
 17         //Enter and connect until you enter“ stop"
 18         do{
 19             nXiaoZhiYv++;
 20             System.out.println("Enter numbers("+(nXiaoZhiYv + 1)+").Type stop if you want to stop.");
 21             str = scan.nextLine();
 22             if(str.equals("stop")){     //Prevent error caused by input string of integer linked list
 23                 break;
 24             }
 25             Chain chain = new Chain(Integer.parseInt(str));
 26             connect(head, chain);
 27         }while (!str.equals("stop"));
 28 
 29         //delete
 30         System.out.println("Delete?(y/n)");
 31         if (scan.nextLine().equals("y")){
 32             System.out.println("Please enter the node you want to delete:");
 33             int node = scan.nextInt();
 34             delete(head, node);
 35         }
 36 
 37         //insert
 38         System.out.println("Insert?(y/n)");
 39         if(scan.next().equals("y")){                      //Not here next.Line,Otherwise, it will read the rest of the linked list
 40             System.out.println("Please enter the location where you want to insert the node:");
 41             int node = scan.nextInt();
 42             System.out.println("Please enter an element for this node:");
 43             int element = scan.nextInt();
 44             insert(head, element, node);
 45         }
 46 
 47 
 48         //output
 49         PrintLinkedList(head);
 50 
 51         //1.File creation (file class instantiation)
 52         File file = new File("D:\\test6","Chain.txt");
 53         //2.File read and write, byte stream read and write, write first and then read
 54         OutputStream outputStream = new FileOutputStream(file);
 55         byte[] insert2 = { 11 , 13 };                //Define byte stream array
 56         outputStream.write(insert2);
 57 
 58         InputStream inputStream = new FileInputStream(file);
 59         int[] num = new int[2];
 60         int by = 0;
 61         while (inputStream.available() > 0){                 //Read and store byte stream with array
 62             num[by] = inputStream.read();
 63             by++;
 64         }
 65         outputStream.close();
 66         inputStream.close();                     //end
 67 
 68         //Output file content
 69         System.out.print("File content is: ");
 70         for(int i = 0; i < 2; i++) {
 71             System.out.print(num[i] + " ");
 72         }
 73         System.out.print("\n");
 74 
 75         //Insert the first number of the file into the fifth digit of the linked list,And output
 76         insert(head, num[0], 5);
 77         PrintLinkedList(head);
 78         //Insert the second number of the file into position 0 of the linked list,And output
 79         insert(head, num[1], 1);
 80         PrintLinkedList(head);
 81         //Delete the first number of the file from the linked list,And output
 82         delete(head, 6);
 83         PrintLinkedList(head);
 84 
 85         rank();
 86         PrintLinkedList(head);
 87     }
 88 
 89     //Connection between linked lists, tail interpolation, traversal
 90     public static void connect(Chain head, Chain chain2){
 91         Chain head2 = head;
 92         while (head2.getNext() != null){
 93             head2 = head2.getNext();
 94         }
 95         head2.setNext(chain2);
 96     }
 97 
 98     //Static method for output
 99     public static void PrintLinkedList(Chain head){
100         Chain temp = head;
101         String list = "";
102         while (temp != null){
103             list = list + " " + temp.getElement();
104             temp = temp.getNext();
105         }
106         System.out.println(list);
107         System.out.println("Total number of elements:" + nXiaoZhiYv);
108     }
109 
110     public static void delete(Chain head, int node){
111         Chain temp = head;
112 
113         if(node == 1) {                //Delete header node
114             Chain_2.head = head.getNext();
115         }
116         else {                          //Traverse to the node to delete
117             for(int i = 1; i < node - 1; i++){
118                 temp = temp.getNext();
119             }
120         }
121 
122         temp.setNext(temp.getNext().getNext());    //Skip this node to delete it
123         nXiaoZhiYv--;                              //Total minus 1
124     }
125 
126     public static void insert(Chain head, int element, int node){
127         Chain insert = new Chain(element);
128         Chain temp = head;
129 
130         if(node == 1){
131             insert.setNext(head);
132             Chain_2.head = insert;
133         }
134         else {
135             for(int i = 0; i < node - 2; i++){
136                 temp = temp.getNext();
137             }
138             insert.setNext(temp.getNext());
139             temp.setNext(insert);
140         }
141         nXiaoZhiYv++;
142     }
143 
144     public static void rank(){
145         Chain temp = Chain_2.head;
146         Chain temp1 = Chain_2.head;              //Double pointer for sorting
147         int t , w = 1, e = 1;            //t The maximum value after storing the current position of the linked list, w Record the pointer position, e Record the position of the number of duplicates after sorting
148 
149         for(int i = 1; i < nXiaoZhiYv; i++){
150             t = temp.getElement();
151             while (temp1.getNext() != null){
152                 temp1 = temp1.getNext();
153                 w++;
154                 if(temp1.getElement() > t){
155                     t = temp1.getElement();
156                     e = w + 1;
157                 }
158             }
159             insert(head, t, i);        //Put the maximum value in the header
160             delete(head, e);           //Number of remaining after deleting the move
161             PrintLinkedList(head);
162             w = i + 1;
163             if(e <= w) temp = temp.getNext();          //Difficulties are encountered here. The problem is that after the following numbers are inserted into the current position, temp Has been moved back one bit,So add if
164             temp1 = temp;
165             if(temp1.getNext() == null) break;         //Prevention of cross-border
166         }
167     }
168 }

↑ is all the codes of the first few steps of Experiment 6,

Fortunately, all the experimental results were right

Congratulations! Congratulations

 

 

 

4. Implement experiments (1) and (2) on android

5. Experiment on android platform (3)

I'm working on it. I'll get it out right away...

 

3, Problems and solutions in the experiment
-Question 1: the Android programming platform is crazy about reporting errors, one step at a time, or even two or three at a time. It's terrible
-Solution to the problem: Baidu, Baidu, or * * Baidu, csdn contracted my solution to report errors at every step

-Question 2: in the linked list
-Problem solution: use String a = "" + t (user-defined variable) inside the method to convert the user-defined variable to String type,

 

4, Experimental feeling

It's still very difficult. The Android platform has a better mentality than the previous server, and the online tutorials are not completely right. I just stubbornly did it bit by bit. I thought I wouldn't be able to program anything now. As a result, I still thought about the experimental topic for a long time, and then compiled it slowly. This experiment hasn't been completed, and the next experiment has been released, Tired, destroy it. The next experiment should be simpler than this, but why is there an Android platform? Tired, that's it