Java Programming 2

1. Write a Java program to answer about the statistical information such as arithmetic mean, median, mode, and standard deviation of an integer data set. (The arithmetic median, median, and mode mean that the arithmetic average, mid-point of the distribution, and most frequent response, respectively.) The input data can be generated by random method or keyboard. Your program should display the output similar to the one shown below.

   
   

   package assignment;

   import java.util.*;

   public class Assignment {

   
   

   public static void main(String[] args) {

   var scanner = new Scanner(System.in);

   System.out.print("Enter number of data points: ");

   int length = scanner.nextInt(); //get length from user.

   int[] arr = new int[length]; //initialize array

   for(int i=0; i<length; i++) { //loop by length

   System.out.print("int[" + i + "]: ");

   arr[i] = scanner.nextInt(); //get data from user.

   }

   BubbleSort(length, arr); //sorting

   System.out.print("Statistical Information: \n"

   + "------------------------------------ \n");

   System.out.format("Arithmetic mean: %.6f\n", mean(arr));

   System.out.format("Median: %.1f\n", median(arr));

   System.out.format("Mode: %d\n", mode(arr));

   System.out.format("Standard Deviation: %.6f\n", deviation(arr));

   }

   public static void BubbleSort(int length, int[] array) { //get length and array

   int temp = 0; //for swap

   for (int i=0; i<length-1; i++) { //descending sorting

   for (int j= i+1; j<length; j++) {

   if (array[i] < array[j]) {

   temp = array[i];

   array[i] = array[j];

   array[j] = temp;

   }

   }

   }

   }

   public static double mean(int[] array) {

       double sum = 0.0;

       for (int i = 0; i < array.length; i++) {

           sum += array[i];

       }

       return sum / array.length;

   }

   public static double median(int[] array) {

       int middle = array.length/2;

       if (array.length%2 == 1) {

           return array[middle];

       }

       else {

           return (array[middle-1] + array[middle]) / 2.0;

       }

   }

   public static int mode(int[] array) {

       int max_Value = 0;

       int max_Count = 0;

   
   

       for (int i = 0; i < array.length; ++i) {

           int count = 0;

           for (int j = 0; j < array.length; ++j) {

               if (array[j] == array[i]) ++count;

           }

           if (count > max_Count) {

           max_Count = count;

               max_Value = array[i];

           }

       }

       return max_Value;

   }

   public static double deviation(int[] array) {

           double sum = 0.0, standardDeviation = 0.0;

           int length = array.length;

   
   

           for(double num : array) {

               sum += num;

           }

   
   

           double mean = sum/length;

   
   

           for(double num: array) {

               standardDeviation += Math.pow(num - mean, 2);

           }

   
   

           return Math.sqrt(standardDeviation/length);

       }

   }

   
   
   
   

2. Write a program that adds the arguments and return the result as follows. You should use the concept of overloading in your program.

   add(1, 2)  --> 3

   add(1, 2, 3) --> 6

   add(1.4, 4.5) -->5.9

package assignment;

import java.util.*;

public class Assignment {

public static void main(String[] args) {

System.out.println("add(1,2) ==> " + add(1,2));

System.out.println("add(1,2,3) ==> " + add(1,2,3));

System.out.println("add(1.4,4.5) ==> " + add(1.4,4.5));

}

public static int add(int a, int b) { //add function for two integers

return a+b;

}

public static int add(int a, int b, int c) { //add function for three integers

return a+b+c;

}

public static double add(double a, double b) { //add function for two doubles

return a+b;

}

}

3. Write a program that will read a sequence of positive real numbers entered by the user and will print the same numbers in sorted order from smallest to largest. The user will input a zero to mark the end of the input. Assume that at most 100 positive numbers will be entered.

   package assignment;

   
   

   import java.util.*;

   
   

   public class Assignment {

   public static void main(String[] args) {

   var scanner = new Scanner(System.in);

   double data = 1;

   double[] array = new double[100];

   int n = 0;

   while(data != 0 && n<100) { //most 100 positive numbers.

   System.out.print("Input real number: ");

   data = scanner.nextDouble();

   if (data < 0) {

   System.out.println("data didn't save. must be positve number.");

   continue;

   }

   array[n] = data;

   n++;

   
   

   //sorting

   for(int i=0; i<n-1; i++) {

   for(int j=n-1; j>i; j--) {

   if (array[j-1] > array[j]) {

   double temp = array[j-1];

   array[j-1] = array[j];

   array[j] = temp;

   }

   }

   } //sorting end.

   for(int i=0; i<n; i++) { //after sorting print array.

   System.out.print(array[i] + ", ");

   }

   System.out.print("\n");

   }

   System.out.println("program exit!");

   }

   }

   
   

   
   

4. Design a class hierarchy that simulates the things you have. For example, you have many electric devices such as laptop computer, smartphone, and mp3 player, many clothes such as pants, skirts, and jumper, etc. Your design should include abstract classes. Write a program that prints class name, instance variables, and methods of all classes. (Note: Draw your class hierarchy in your document.)

   
   

   아래의 클래스구조와 같이 hierarchy를 설계함.

   

   Device.java

   package device;

   
   

   public abstract class Device {

   public abstract void hardware();

   public abstract void software();

   public void turnOn() {

   System.out.println("Turn on the device.! Hi!!");

   }

   public void turnOff() {

   System.out.println("Turn off the device.! Bye~");

   }

   public static void main(String[] args) {

   Device macbook = new Macbook();

   Device lte_controller = new LTE_controller();

   Device externalmonitor = new ExternalMonitor();

   macbook.hardware();

   macbook.software();

   macbook.turnOn();

   macbook.turnOff();

   System.out.print("\n");

   
   

   lte_controller.hardware();

   lte_controller.software();

   lte_controller.turnOn();

   lte_controller.turnOff();

   System.out.print("\n");

   
   

   externalmonitor.hardware();

   externalmonitor.software();

   externalmonitor.turnOn();

   externalmonitor.turnOff();

   
   

   }

   
   

   }

   ExternalMonitor.java

   package device;

   
   

   public class ExternalMonitor extends Device{

   public void connect_Macbook() {

   System.out.println("ExternalMonitor connect_Macbook()");

   }

   public void disconnect_Macbook() {

   System.out.println("ExternalMonitor disconnect_Macbook()");

   }

   
   

   @Override

   public void hardware() {

   System.out.println("ExternalMonitor hardware() --> 27inch display");

   }

   
   

   @Override

   public void software() {

   System.out.println("ExternalMonitor software() --> realtime OS");

   }

   }

   
   

   Ipad.java

   package device;

   
   

   public abstract class Ipad extends Device{

   @Override

   public void hardware() {

   System.out.println("iPad hardware() --> A10X Fusion");

   }

   
   

   }

   LTE_controller.java

   package device;

   
   

   public class LTE_controller extends Ipad {

   
   

   @Override

   public void software() {

   System.out.println("LTE_controller software() --> ARM asm");

   }

   }

   
   

   Macbook.java

   package device;

   
   

   public class Macbook extends Device {

   
   

   @Override

   public void hardware() {

   System.out.println("Macbook hardware() --> intel i7");

   }

   
   

   @Override

   public void software() {

   System.out.println("Macbook software() --> Macintosh");

   }

   
   

   }

   
   

   
   

5. Write a program that uses the methods of ArrayList. This program prints 10 numbers randomly generated between 0 to 20. Your program should provide insert, remove, and search operations. Note that numbers should be sorted after all operations are finished. The following is an example.

   List: 12456810111314 Input your command : a
   Input number to add: 7
   List: 124567810111314 Input your command : r

   Input number to add: 1
   List: 2456810111314 Input your command : s Input number to search: 5 Index of 5 is 2.

   
   

   package assignment;

   import java.util.*;

   public class  Assignment {

   public static void main(String[] args) {

   ArrayList<Integer> array = new ArrayList<Integer> ();

   init_arr(array); //random 0~20 init array.

   print_arr(array); //sorting & print lists.

   var scanner = new Scanner(System.in);

   while(true) {

   System.out.print("Input your command: ");

   String command = scanner.next();

   int num = 0;

   switch(command) {

   case "a":

   System.out.print("Input number to add: ");

   num = scanner.nextInt(); //get number from user.

   array.add(num); //add to array.

   print_arr(array); //print arr.

   break;

   case "r":

   System.out.print("Input number to remove: ");

   num = scanner.nextInt();

   if (array.contains(num)) { //if the number is exist.

   array.remove(Integer.valueOf(num)); //remove from array.

   print_arr(array); //print arr.

   }

   else {

   System.out.println("Remove Error: " + num + " is not found."); //if not exist, error print

   }

   break;

   case "s":

   System.out.print("Input number to search: ");

   num = scanner.nextInt(); //get number from user.

   if (array.contains(num)) { //if the number is exist.

   int index = array.indexOf(num); //save index of num

   System.out.println("Index of " + num + " is " + index); //print result

   }

   else {

   System.out.println("Search Error: " + num + " is not found."); //if not exist, error print

   }

   break;

   default:

   System.out.println("error: wrong command: (A)dd, (R)emove, (S)earch");

   }

   }

   }

   public static void init_arr(ArrayList<Integer> array) { //0~20 random number of 10 lists of array initialize

   boolean same = false;

   int random = (int)(Math.random()*21);

   array.add(random);

   
   

   while(true) { //random number 0~20 without duplicate number.

   random = (int)(Math.random()*21); //initialize new random number.

   
   

   for (int j=0; j<array.size(); j++) { //check duplicate number

   if(random == array.get(j)) { //if same number found.

   same = true;

   break;

   }

   }

   if(same == true) { //if same duplicated number found, 

   same = false; 

   continue; // initialize new random number on the top of loop

   }

   else {

   array.add(random); 

   if(array.size() == 10) //array has 10 list, done.

   break;

   }

   }

   }

   public static void print_arr(ArrayList<Integer> array) { //sorting & print lists function

   Collections.sort(array); //array sorting using collections

   System.out.print("List: ");

   for (int i=0; i<array.size(); i++) { //print all lists.

   System.out.print(array.get(i) + " ");

   }

   System.out.print("\n");

   }

   }

   
   

6. Boggle is a simple game that finds words sequentially linear-connected in a NxN grid. In the following example, you can find 2 words the "FLY", "MOON".

Design a light-weight boggle game that satisfies the following requirements.

1) Make a Boggle with a 3x3 grid.
2) Letters are randomly allocated.
3) User may input the word. Find this word at the grid. 4) Each word is at least three letters.

The following is an output example.

package assignment;

import java.util.*;

public class  Assignment {

public static int xx;

public static int yy;

public static void main(String[] args) {

char [][] boggle = new char[5][5];

char[][] cp_array = new char[5][5];

init_boggle(boggle);

print_boggle(boggle);

while(true) {

System.out.print("Input word: ");

var scanner = new Scanner(System.in);

String input_word = scanner.next();

if (!word_length_checking(input_word)) {

System.out.println("Error: the word length should be 3~9 characters.");

}

else {

for(int i=0; i<5; i++) {

cp_array[i] = boggle[i].clone();

}

if (check_boogle(cp_array, input_word)) {

System.out.println("Exist!");

}

else {

System.out.println("Non-Exist!");

}

}

}

}

public static void init_boggle(char[][] array) { 

final String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    final int N = alphabet.length();

   

    Random r = new Random();

    char random;

char word_array[] = new char[9];

boolean same = false;

int cnt = 0;

    while(true) { //random number 0~20 without duplicate number.

random = alphabet.charAt(r.nextInt(N));; //initialize new random alphabet.

for (int j=0; j<word_array.length; j++) { //check duplicate number

if(random == word_array[j]) { //if same number found.

same = true;

break;

}

}

if(same == true) { //if same duplicated number found, 

same = false; 

continue; // initialize new random number on the top of loop

}

else {

if(cnt == 9) //array has 9 list, done.

break;

for(int i=0; i<9; i++) {

if (word_array[i] == 0) {

word_array[i] = random;

cnt ++;

break;

}

}

}

}

    cnt = 0;

    for(int i=1; i<4; i++) {

    for(int j=1; j<4; j++) {

    array[i][j] = word_array[cnt];

    cnt++;

    }

    }

}

public static void print_boggle(char[][] array) { 

for(int i=1; i<4; i++) {

    System.out.print(" ------------- \n");

    System.out.print(" | ");

    for(int j=1; j<4; j++) {

    System.out.print(array[i][j] + " | ");

    }

    System.out.print("\n");

    }

System.out.print(" ------------- \n");

}

public static boolean check_boogle(char[][] arr, String word) {

String temp = word;

boolean success = false;

char a_char = word.charAt(0);

int i, j = 1;

boolean startingPointFound = false;

for(i=1; i<4; i++) {

for(j=1; j<4; j++) {

if(a_char == arr[i][j]) {

    arr[i][j] = ' ';

    temp = temp.substring(1);

    startingPointFound = true;

    break;

}

}

if (startingPointFound)

break;

}

if (startingPointFound) {

for(int k = 0; k<8; k++) {

if(near_char(arr, temp.charAt(0), i, j) == false) {

break;

}

else {

i = xx;

j = yy;

    temp = temp.substring(1);

}

    if(temp.length() == 0) {

    success = true;

    return true;

    }

}

}

return false;

}

public static boolean near_char(char[][] array, char next ,int i, int j) {

for(int x = i-1; x<i+2; x++) {

for(int y = j-1; y<j+2; y++) {

//System.out.println("++ " + array[x][y]);

if(next == array[x][y]) {

    //System.out.print( "near_char: \""+ next + "\" ");

array[x][y] = ' ';

xx = x;

yy = y;

return true;

}

}

}

return false;

}

public static boolean word_length_checking(String word) {

if(2 < word.length() && word.length() < 10) {

return true;

}

return false;

}

}