lab 10


1.
import java.util.Scanner;

public class Test1{

     public static void main(String []args){
     
        Scanner input = new Scanner(System.in);
        double[] student1Scores = new double[4];
     
System.out.println("How many students do you want to record?");
int noOfStudents = input.nextInt();

String[] names = createNames(noOfStudents);

System.out.println("Please enter their scores:");
         for(int i=0;i<names.length;i++)
{
System.out.println("Enter score for " + names[i]);
            for(int j=0;j<student1Scores.length;j++)
            {
                student1Scores[j] = input.nextDouble();
            }
            double average = averageScore(student1Scores);
System.out.println(names[i] + " average score is " + average);
char grade = determineGrade(average);
System.out.println(names[i] + " grade is then " + grade);
        }
System.out.println("Displaying all names!");
displayNames(names);
        }

public static String[] createNames(int noOfStudents)
{
String[] n = new String[noOfStudents];

Scanner input = new Scanner(System.in);
System.out.println("Please enter " + noOfStudents  + " student's names");
        for(int i=0;i<n.length;i++)
        {
            n[i] = input.nextLine();
        }
System.out.println("You have entered all names!TQ");
return n;
}

public static void displayNames(String[] names)
{
for(int i=0;i<names.length;i++)
{
System.out.println(names[i]);
}
}
 
     public static char determineGrade(double average)
{
if(average > 90)
return 'A';
else if(average > 80)
return 'B';
else return 'C';
}

     public static double averageScore(double[] x)
     {
     
         double sum = 0;
         for(int i=0; i<x.length;i++)
         {
             sum = sum + x[i];
         }
         double average = sum/x.length;
         return average;
     }


}

2.
import java.util.Scanner;
public class Test2{
public static void main (String[] args){
Scanner input=new Scanner(System.in);
System.out.println("Enter number of rows and column of array:");
int rows = input.nextInt();
int columns=input.nextInt();
double [][]table=new double[rows][columns];
System.out.println("Enter array:");
for(int i=0;i<table.length;i++)
{
for(int j=0;j<table[i].length;j++)
{
table[i][j]=input.nextDouble();
}
}
int[] location=locateLargest(table);
System.out.printf("The location of the largest element is (%d,%d)%n",location[0],location[1]);
}

public static int []  locateLargest(double[][]a)
{
int [] location=new int [] {0,0};
double largest=a[0][0];
for (int i=0;i<a.length;i++)
{
for(int j=0;j<a[i].length;j++)
{
if(largest<a[i][j])
{
largest=a[i][j];
location[0]=i;
location[1]=j;
}
}

}
return location;
}
}

3.
import java.util.Scanner;
public class Test3{

     public static void main(String []args){
         final int Total_numbers=6;
         int[] numbers = new int[Total_numbers];
         Scanner input=new Scanner (System.in);
        System.out.println("Enter" + number.length + "integer numbers: ");
        //Read all numbers
        for (int i=0;i<numbers.length;i++)
        {
            number[i]=input.nextInt();
        }
        //find the largest element
        int max=numbers[0];
        for (int i=1;i<numbers.length;i++)
        {
            if (numbers[i]>max)
            {
                max=numbers[i];
            }
        }
        //find the smallest element
        int min=number[0];
        for (int j=1;j<numbers.length;j++)
        {
            if (numbers[j]<min)
            {
                min=numbers[j];
            }
        }
        //find the occurence of the largest number
        int count1=0;
        for(inti=0; i<numbers.length;i++)
        {
            if(numbers[i]==max)
            count1++;
        }
        //find the occurence of the smallest number
        int count2=0;
        for(int j=0;j<numbers.length;j++)
        {
            if(numbers[j]==min)
            count2++;
        }
        int swap=numbers[0];
        for(int i=0; i<numbers.length/2;i++)
        {
            int temp=numbers[i];
            numbers[i]=numbers[numbers.length-i-1];
            numbers[numbers.length-i-1]=temp;
        }
        //prepare the result
        System.out.println("Output:");
        System.out.println("The array is:");
        for (int i=0; i<numbers.length;i++)
        {
            System.out.println(numbers[i] + "");
         
            System.out.println();
            System.out.println("The largest number is " + max);
            System.out.println("The smallest number is" + min);
            System.out.println("The occurrence count of the largest number is" + count1);
            System.out.println("The occurence count of the smallest number is" + count2);
         
         
        }
    }
     
 }
}



4.
import java.util.Scanner;
public class Test4 {
public static void main(String[] args){
Scanner input=new Scanner(System.in);
final int maxrange=10;
final int minrange =-1;
final int range=10;

int[] list=new int[maxrange];

for(int i=0; i<list.length;i++)
{
list[i]=0;
}
System.out.println("Enter a list of integer between 1 and 100");
System.out.println(" To stop, enter an integer not in this range");
System.out.println("Enter integer");
int value= input.nextInt();
while (value>=minrange && value<=(maxrange*range))
{
list[(value-1)/range]=list[(value-1)/range]+1;
System.out.println("Enter integer");
value=input.nextInt();
}
System.out.println("Here is your histogram");
for (int i=0;i<list.length;i++)
{
System.out.println(" " + (i*range+1) + " " + (i+1)*range+ "\t|");
for (int j=0; j<list[i];j++)
{
System.out.println("*");
}
System.out.println();
}
}
}

Lab 9

1.
a. Create an array to hold 10 double values.
double[] list = new double[10];
b. Assign the value 5.5 to the last element in the array.
 list[list.length - 1] = 5.5;
c. Display the sum of the first two elements. 
System.out.println(list[0] + list[1]);
d. Write a loop that computes the sum of all elements in the array. 

double sum = 0;

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

                                   sum += list[i];

e. Write a loop that finds the minimum element in the array.

double min = list[0];

                       for (int i = 1; i < list.length; i++)

                                   if (min > list[i])  min = list[i];

f. Randomly generate an index and display the element of this index in the array.
System.out.println(list[(int)(Math.random() * list.length)]);
g. Use an array initializer to create another array with the initial values 3.5, 5.5, 4.52 and 5.6.
double[] list = {3.5, 5.5, 4.52, 5.6};

2.
public class Test{

     public static void main(String []args){
         double[] r= new double[100];
         for (int i = 0; i < r.length; i++)
         {
         r[i] = (int)(Math.random() * r.length);
         }
        System.out.println(r[1]);
     }

}

3.

import java.util.Scanner;
public class karyeeTest3{

     public static void main(String []args){
         int n, temp;
         Scanner input = new Scanner(System.in);
         System.out.println("Enter number of array");
         n= input.nextInt();
         int values[]=new int[n];
         System.out.println("Enter all the values");
         for (int i = 0; i < n; i++)
         {
            values[i]=input.nextInt();
         }
         for (int i=0;i<n;i++)
         {
             for(int j=i;j<n;j++)
             {
                 if(values[i]>values [j])
                 {
                     temp=values[i];
                     values[i]=values[j];
                     values[j]=temp;
                     
                 }
             }
         }
        System.out.println("increasing order");
        for (int i=0; i<n; i++)
        {
            System.out.println(values[i]);
        }
     }

}

4.
import java.util.Scanner;
public class Test4{

     public static void main(String []args){
         int n;
         int temp = 0;
         Scanner input = new Scanner(System.in);
         System.out.println("Enter number of array");
         n= input.nextInt();
         int[] values=new int[n];
         int[] count=new int[n];
         for (int i = 0; i < values.length; i++)
         {
            values[i]= (int)((Math.random() *9) +1);
         }
         System.out.print("Values are");
         for (int i=0;i<values.length;i++)
         {
             System.out.print(values[i] + "");
         }
        for(int i=0; i<values.length;i++)
                 {
                   temp=values[i];
                   for (int j=0; i<values.length;i++)
                   {
                       if(temp==values[j])
                       {
                           count[i]++;
                       }
                   }
                 }

    System.out.println();
    for (int i=0;i<count.length;i++)
    {
        if(count[i]>1)
        {
            System.out.println(values[i]+ "occurs" + count[i] + "times");
         }
else
            {
                System.out.println(values[i] + "occurs" + count[i] + "time");
            }
    }
     }

}

5.


import java.util.Scanner;
public class karyeeTest5{

     public static void main(String []args){
    int[] score=new int[100];
    int sum=0;
    int num=0;
    int numOfScores;
    double average= numOfScores=0;
    Scanner input= new Scanner(System.in);
    System.out.println("Enter score(Negative number signifies end):");
    for (int i=0; i<score.length; i++)
    {
        score[i]=input.nextInt();
        if (score[i] <0)
        break;
        sum+= score[i];
        num++;
    }
    average =sum/sum;
    int aboveOrEqual;
    int below;
    aboveOrEqual=below=0;
    for(int i=0; i< num;i++)
    {
        if(score[i]>=average)
        {
            aboveOrEqual++;
        }
    else
    {
        below++;
    }
    }
    System.out.println("Average of score is" + average);
    System.out.println("Number of scores above or equal to average is" + aboveOrEqual);
    System.out.println("Number of scores below average" + below);
     }
    

}

6.


import java.util.Scanner;
public class karyeeTest6{

     public static void main(String []args){
    int num=0;
    double[] values=new double[10];
    Scanner input= new Scanner(System.in);
    System.out.println("Enter 10 values");
    for (int i=0;i<values.length;i++)
    {
        values[i]=input.nextDouble();
    }
    System.out.println("Average of integer" + (int)average(values));
    System.out.println("Average of double values" + average(values));
     }
    
    public static int average(int[] array)
    {
        int sum=0;
        for (int i=0;i <array.length;i++)
        {
            sum += array[i];
        }
        int average=sum/array.length;
        return average;
    }
    public static double average(double[] array)
    {
        double sum=0;
        for(int i=0; i<array.length;i++)
        {
            sum+= array[i];
        }
        double average=sum/array.length;
        return average;
    }

}

7.


import java.util.Scanner;
public class karyeeTest7{

     public static void main(String []args){
    int num=0;
    double[] values=new double[10];
    Scanner input= new Scanner(System.in);
    System.out.println("Enter 10 values");
    for (int i=0;i<values.length;i++)
    {
        values[i]=input.nextDouble();
    }
   System.out.println("The maximum value is" + max(values));
   
    }
    public static double max(double[]array)
    {
        double max=0.0;
        for (int i=0;i<array.length;i++)
        {
            if(array[i]>max)
            max=array[1];
        }
        return max;
    }

}

8.
import java.util.Scanner;
public class Test8{
     public static void main(String []args){
    Scanner input= new Scanner(System.in);
    System.out.println("Enter number of student");
    int n=input.nextInt();
    int[] noOfStudents=new int[n];
    String[] name=new String[n];
    int[] score=new int [noOfStudents.length];
    System.out.println("Enter each student's name and score");

    for (int i=0;i<noOfStudents.length;i++)
    {
        System.out.println("Student" + (i+1) + "\nName:" + " ");
        name[i]=input.next();
        System.out.println("Score: ");
        score[i]=input.nextInt();
    }

    sortDecreasing(name,score);
    for (String e:name)
    {
        System.out.println(e);
    }

    }

    public static void sortDecreasing(String[]name, int[] noOfStudents)
    {
        for (int i=0; i<noOfStudents.length;i++)
        {
            int max = noOfStudents[i];
            int maxIndex=i;
            String temp;
            for(int j=i;j<noOfStudents.length;j++)
            {
                if (noOfStudents[j]>max)
                {
                    max = noOfStudents[j];
                    maxIndex=j;
                }
            }
            if(maxIndex !=i)
            {
                temp=name[i];
                name[i]=name[maxIndex];
                name[maxIndex]=temp;
                noOfStudents[maxIndex]=noOfStudents[i];
                noOfStudents[i]=max;
            }
        }
    }

}

Lab 8

Choong Kar Yee

182630

1.

import java.util.Scanner;
public class Test1{
public static void main(String[] args){
Scanner input=new Scanner(System.in);

int i=1;
int noOfStudents=2;

while(i<= noOfStudents){
System.out.println("Enter first test score");
double test1=input.nextDouble();
System.out.println("Enter second test score");
double test2=input.nextDouble();
System.out.println("Enter labwork score");
double labwork=input.nextDouble();
System.out.println("Enter final exam score");
double exam=input.nextDouble();

double mark=test1+test2+labwork+exam;


System.out.println("Enter the mark" + mark);
System.out.println("Your grade is " + grade(mark));
i++;
}}

public static char grade(double mark){

char grade;

if (mark>=80)
{
grade='A';
}
else if (mark>=60)
{
grade='B';
}
else grade='F';

return grade;
}
}

2.

import java.util.Scanner;
public class Test2{
public static void main(String[] args){
Scanner input=new Scanner(System.in);

//System.out.println("Enter a character");
//char a=input.next().CharAt(0);
System.out.println("Enter a String");
String str=input.nextLine();

System.out.println("The number of letters in the string \"" + str + "\": " + countLetters(str));


}

public static int countLetters(String str){


int count =0;
for (int i=0; i<str.length();i++)
{
if (Character.isLetter(str.charAt(i)))

count++;
}
return count;
}
}

import java.util.Scanner;

public class Test2_b {

/** Main Method */

public static void main(String[] args) {

Scanner input = new Scanner(System.in); // Create a Scanner

// Prompt the user to enter a string followed by a character

System.out.print(

"Enter a string followed by a character e.g. Welcome, e : " );

String string = input.nextLine();

// Extract character and substring

int k = string.indexOf(", ");

String str = string.substring(0, k);

char ch = string.charAt(k + 2);

// Display the nubmer of occurrences of the character in the string

System.out.println(

"The number of occurrences of \"" + ch + "\" in \'" + str + "\" is: " +

count(str, ch));

}

/** Method count */

public static int count(String str, char a) {

int count = 0; // Initialize count to 0

// Count the number of occurrences of the character a in the string str

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

if (a == str.charAt(i))

count++;

}

return count;

}

}

https://github.com/jsquared21/Intro-to-Java-Programming/blob/master/Exercise_06/Exercise_06_23/Exercise_06_23.java