Bubble Sorting in Java

Bubble sort is a sorting algorithm that works by repeatedly iterating through the array comparing each pair of adjoining elements and swapping them if they are in the wrong order.

Let us understand how Bubble sorting works with diagrammatic representation:

Say for example, if we have array elements as shown below:

65, 47, 70, 9

Pass 1:

To begin with, the element at 0th and 1st index are compared. Their positions are swapped, if element at 0th index is greater than element at 1st index.

Since, 65 is greater than 47, swap occurs.

Now, elements at 1st and 2nd index are compared.

Since, 65 is less than 70, no swap required.

Now, elements at 2nd and 3rd index are compared.

Since, 70 is greater than 9, swap occurs and now, the list will look like this.

In the next pass, the second highest number is placed in the second last position and so on.  This process will keep on repeating until the entire array is sorted.

Below program will teach you how to sort the numbers in an array using Bubble Sorting.

class BubbleSort
{
    public static void main(String[]args)
    {
        int list[] = {65,47,40,9,37,72,45,17};
        int len = list.length;
        for(int i = 0;i<len-1;i++)
        {
            for(int j = 0;j<len-i-1;j++)
            {
                if(list[j]>list[j+1])
                {
                    //swapping of adjacent elements done here
                    int tmp = list[j];
                    list[j] = list[j+1];
                    list[j+1] = tmp;
                }
            }
        }
        System.out.println("Sorted array is");
        for(int i = 0;i<len-1;i++)
        {
            System.out.println(list[i]);
        }
    }
}

Demonstration:

1. A class namely BubbleSort have been defined.
2. A main method have been defined.
3. An array namely list of int data type has been declared and unsorted elements are stored in it.
4. Stores the length of list in len variable.
5. The outer loop iterates through the entire array.

6. Inner loop iterates through the remaining unsorted array only. It is done by subtracting the value of counter variable i in inner loop test condition (len-i-1).
7. Compares two adjacent elements, i.e. element at jth position and that as (j+1)th position.
8. Stores the value of the current element in a temporary variable.
9. Stores the value of the next element of the array in the current element.
10. Stores the value of the temporary variable in the next element

Lead Number in Java

If the sum of even digits is equal to the sum of odd digits, then such numbers are called lead numbers.

Example: 3669,3544 etc

Say for example, if you have 3669 then sum of even numbers in the given number

6+6 = 12

Sum of odd numbers in the given number

3+9 = 12

As it can be seen that sum of even numbers and sum of odd numbers are equal. Hence, it is a Lead number.

Let's see the Java program to determine if a number is LEAD Number or not.

import java.util.Scanner;
class LEAD 
{
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);
        int n, sum1 = 0,sum2 = 0;
        System.out.println("Enter a number");
        n = sc.nextInt();
        while(n!=0)
        {
            int d = n%10;
            if(d%2==0)
            {
                sum1 = sum1+d;
            }
            else
            {
                sum2 = sum2+d;
            }
        n = n/10;
        }
        if(sum1 == sum2)
        {
            System.out.println("Given number is a lead number");
        }
        else
        {
            System.out.println("Given number is not a lead number");
        }
    }
}

Demonstration:

1. First, Scanner class is imported.
2. A class namely LEAD have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.
6. To accept and store the number, a variable namely n has been defined of int data type

7. Then, two different variables namely

    a) sum1 - This variable will store the sum of even digits. First, it is initialized with 0.

    b) sum2 - This variable will store the sum of odd digits. First, it is initialized with 0.

Now, let us see the working:

while(n!=0)

This loop iteration will continue till the index position doesn't becomes 0.

Refer to the below diagram for clear understanding.

As it can be seen that loop will start its operation from index position 3 and the element at index 3 is 9. It will continue till index position 0 reaches.

For example, in first loop iteration, first element 9 will be extracted, then with the help of if else statement, it will be examines if 9 is divisible by 2 or not. If it is divisible by 2, then the number will be added to the sum1 variable or else it will be added to the sum2 variable. In this case, 9 is not divisible by 2 and hence, it will be added to the sum2 variable.

Like this, it will keep on checking the individual numbers until the index position does not reaches 0.

n = n/10; will ensure that the number is deleted permanently deleted.

In previous operation, we have seen that the first extracted number using n%10 was 9. Immediately, after the if...else operation, n = n/10; will be executed which means 3669 is now going to be divided by 10 resulting to 366.9. This operation will permanently delete this 9 from n variable. so that in next iteration, 9 doesn't gets counted during execution of the while loop. Like this, it will keep on deleting the digits from n variable.

Here is the final outcome of the program:

As 3669 is taken as the example, hence

sum1 is carrying = 12 (i.e. 6+6)

sum2 is carrying = 12 (i.e. 3+9)

Now, with the help of if...else conditional statement outside the while loop, it is getting identified if the numbers contained within sum1 and sum2 variables are equal or not. If they are equal, it is a Lead number or else, it is not a lead number.

Now, write this program and test it with various numbers and increase your knowledge.

Happy Coding.......

String case conversion and replacing vowel with next character following it

Write a Java Program to accept a string from user, convert it into uppercase and then replace the vowels with the next character following it.

Hint:

Input: Computer

Output: CPMPVTFR

Answer:

import java.util.Scanner;

class Vowelreplace

{

    public static void main(String[]args)

    {

        Scanner sr = new Scanner(System.in);

        int i,len;

        String word,newword = "";

        char ch;

        System.out.println("Enter a Word:");

        word = sr.nextLine();

        word = word.toUpperCase();

        len = word.length();

        for(i = 0;i<len;i++)

        {

            ch = word.charAt(i);

            if(ch=='A'||ch=='E'||ch=='I'||ch=='O'||ch=='U')

            {

                char nextchar = (char)(ch+1);

                newword = newword+nextchar;

            }

            else

            {

                newword = newword+ch;

            }

        }

        System.out.println("The converted string is:"+newword);

    }

}

Demonstration:

1. First, Scanner class is imported.
2. A class namely Vowelreplace have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. To accept and store the word, a variable namely word has been defined of String data type.

6. Another variable namely newword has been declared for holding the converted string and a blank space has been assigned to it using "".

7. The variable ch will contain the individual characters in a string on basis of index positions.

8. A word has been demanded from user by giving a message.

9. The user input will get stored into word namely variable.

10. Then, the entered word will be converted to uppercase letters using string accessor method.

11. Then, length of the entered word will be stored in an integer variable namely len.

12. Then, a for loop will iterate and iteration will start for the variable namely i which is assigned with the value of 0. It means that loop will start from 0 index position and it will keep on executing till i doesn't reach less than length of the word.

13. In each loop iteration, ch will contain the individual character from the 1st index position.

14. Then, with the conditional statement, it will be determined if ch is containing any vowel or not.

15. Then, another character variable namely nextchar has been declared and with typecasting, character has been incremented by 1 which means, if any vowel is detected, then, that vowel will be added by 1 which in turn will display next character following that vowel.

16. Then, newword variable will add the previous blank space with the value at nextchar.

17. If any vowel doesn't gets detected, then the statement at the else block will get executed.

18. Finally, the entire converted word gets stored in newword variable which has been displayed outside the if...else block as it can be seen in the program.

Now, write this program and test it with various words and increase your knowledge.

Happy Coding.......

NEON Number - Java

A neon number is a number where the sum of digits of the square of the number is equal to the number.

Example: 0,1 and 9

Say for example, if you have 9 then square of 9 is 81.

8+1 = 9

As it can be seen that sum of digits of the square of the number is equal to the number. Hence, it is a NEON number.

Let's see the Java program to determine if a number is NEON Number or not.

import java.util.Scanner;

class NEON

{

    public static void main(String[]args)

    {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a number");

        int n = sc.nextInt();

        int sum = 0,temp = n, square;

        square = n*n;

        while(square!=0)

        {

            sum+=square%10;

            square/=10;

        }

        if(sum == n)

        {

            System.out.println("It is a NEON number");

        }

        else

        {

            System.out.println("It is not a NEON number");

        }

    }

}

Demonstration:

1. First, Scanner class is imported.
2. A class namely NEON have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.
6. To accept and store the number, a variable namely n has been defined of int data type

7. Then, three different variables namely

    a) sum - This variable will store the sum of digits in the variable square. First, it is initialized with 0.

    b) temp - This variable will hold the number given by user on temporary basis.

    c) square - This variable will store the square of the number given by user.

Now, let us see the working:

square = n*n;

This above operation will evaluate the square of the number given by user. Say for example, user gave 9. Here, first square of 9 will be evaluated using this statement.

while(square!=0)

This loop will continue its iteration until value of square doesn't become equals to 0.

Square of 9 is 81. So, first 1 will be extracted, then 8 will get extracted as it is in index 0. Refer to the below diagram for clear understanding.

sum+ = square%10;

Here, we need to understand few things.

First, individual digits from number is getting extracted using square%10.

As in case of 81, the first extracted number using square%10 will be 1.

Then, this number will get added to the variable sum.

Similarly, second number using square%10 will be 8 and it will also be added to sum.

Now, sum is containing 1+8 = 9

square/=10;

In previous operation, we have seen that the first extracted number using square%10 was 1. Immediately, after this operation, square/=10; will be executed which means 81 is now going to be divided by 10 resulting to 8.1. This operation will permanently delete this 1 from square variable. so that in next iteration, 1 doesn't gets added to the sum variable again. Like this, it will keep on deleting the digits from square variable.

Here is the final outcome:

sum is now containing sum of square of number i.e. 8+1 = 9

n variable is containing the number i..e 9

Finally, with the conditional statement using if-else, it is determined if sum is equal to n or not as it can be seen in the program. If sum is equal to n, then it is displaying that the number is a NEON number. Otherwise, it is displaying that the number is not a NEON number.

Now, write this program and test it with various numbers and increase your knowledge.

Happy Coding.......

Dudeney Number - Java

A Dudeney number is a positive integer for which the sum of its digits is equal to the the cube root of the number itself.

For example - 512

5+1+2=8

8³ = 512

Here is the java code for determining if a number is Dudeney or not.

import java.util.Scanner;
class Dudeney
{
    public static void main(String[]args)
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter a number");
        int n = sc.nextInt();
        int sum = 0,temp = n, cube = 0;
        while(temp!=0)
        {
            sum+=temp%10;
            temp/=10;
        }
        cube = sum*sum*sum;
        if(cube == n)
        {
            System.out.println("It is a Dudeney number");
        }
        else
        {
            System.out.println("It is not a Dudeney number");
        }
    }
}

Demonstration:

1. First, Scanner class is imported.
2. A class namely Dudeney have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.
6. To accept and store the number, a variable namely n has been defined of int data type

7. Then, three different variables namely

    a) sum - First, the individual digits will be extracted due to the presence of temp%10. Then, these individual digits shall get added to sum.

    b) temp - This variable will hold the number given by user on temporary basis. Actually, entire operation will be done with temp variable. temp = n means the value stored in n namely variable is getting assigned to temp. It means that throughout the entire operation, original value stored in n namely variable will remain safe.

    c) cube - This variable will hold the cube of the number that is stored in sum.

Now, let us see the working:

while(temp!=0)

This loop will continue its iteration until value of temp doesn't become equals to 0. Say for example, user gave 512. Here, first 2 will be extracted, then 1 and at last, 5 will get extracted as it is in index 0. Refer to the below diagram for clear understanding.

sum+ =temp%10;

Here, we need to understand few things.

First, individual digits from given number is getting extracted using temp%10 and getting stored in sum.

As in case of 512, the first extracted number using temp%10 will be 2.

Similarly, second number using temp%10 will be 1 and it will also be added to sum.

At last, third number using temp%10 will be 5 and it will also be added to sum.

Now, sum is containing 2+1+5 = 8

temp/=10;

In previous operation, we have seen that the first extracted number using temp%10 was 2. Immediately, after this operation, temp/=10; will be executed which means 512 is now going to be divided by 10 resulting to 51.2. This operation will permanently delete this 2 from temp variable. so that in next iteration, 2 doesn't gets added to the sum variable again. Like this, it will keep on deleting the digits from temp variable.

Here is the final outcome:

sum is now containing sum of digits i.e. 5+1+2 = 8

n variable is containing 512

cube = sum*sum*sum;

This operation outside the while loop will find the product of sum variable and that product will be assigned to cube.

Now, cube is containing 512

Finally, with the conditional statement using if-else, it is determined if cube is equal to n or not as it can be seen in the program. If cube is equal to n, then it is displaying that the number is a Dudeney number. Otherwise, it is displaying that the number is not a Dudeney number.

Now, write this program and test it with various numbers and increase your knowledge.

Happy Coding.......

Multiplication Table - Java

This java program will guide you on how to create a multiplication table of a number that is given by the user in the form of an input. In this program, I have taken for loop to demonstrate the whole process.

Below is the java code for printing the multiplication table.

import java.util.Scanner;

class Multiplication_table

{

    public static void main(String[]args)

    {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a number");

        int number = sc.nextInt();

        for(int i = 1;i<=10;i++)

        {

            System.out.println(number+" X "+i+" = "+number*i);

        }

    }

}

Demonstration:

1. First, Scanner class is imported.
2. A class namely Multiplication_table have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.

6. To accept and store the number, a variable namely number has been defined of int data type.
7. Used for loop and initialized an int variable namely i by 1 and given the condition as i<=10 that means, loop will keep on executing from 1 to 10.
8. Within for loop block, System.out.println(number+" X "+i+" = "+number*i); is mentioned which means:
    a) First value in number variable will be displayed. This is the number given by user.
    b) Then, X will be displayed. During final output, you will understand its purpose.
    c) Then, present value of i will be displayed. Due to loop, it will keep on executing from 1 to 10.
    d) Finally, product of number and i will get displayed.

Output of the code will be as displayed in the below diagram. As it can be seen that as per demanded by the program to enter a number, we have given 15 which means that multiplication table of 15 needs to be displayed.

Immediately, after pressing enter, the following output will come:

Now, type the program in BlueJ or any other Online Java compiler and run the code and test it with different numbers.

Happy Coding ........

NIVEN Number - Java

 

A NIVEN or HARSHAD number is a number which is divisible by the sum of its digits.

Example:

18 is a NIVEN number

1+8 = 9

18%9 = = 0

Let's start the code of determining if a number is NIVEN or not.

Below is the code for determining if a number is NIVEN.

import java.util.Scanner;

class SUPERSPY

{

    public static void main(String[]args)

    {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a number");

        int n = sc.nextInt();

        int sum = 0,temp = n;

        while(temp!=0)

        {

            sum+=temp%10;

            temp/=10;

        }

        if(n%sum == 0)

        {

            System.out.println("It is a NIVEN number");

        }

        else

        {

            System.out.println("It is not a NIVEN number");

        }

    }

}

Demonstration:

1. First, Scanner class is imported.
2. A class namely NIVEN have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.
6. To accept and store the number, a variable namely n has been defined of int data type

7. Then, two different variables namely

    a) sum - This variable will store the sum of digits. First, it is initialized with 0.

    b) temp - This variable will hold the number given by user on temporary basis. Actually, entire operation will be done with temp variable. temp = n means the value stored in n namely variable is getting assigned to temp. It means that throughout the entire operation, original value stored in n namely variable will remain safe.

Now, let us see the working:

while(temp!=0)

This loop will continue its iteration until value of temp doesn't become equals to 0. Say for example, user gave 18. Here, first 8 will be extracted and at last, 1 will get extracted as it is in index 0. Refer to the below diagram for clear understanding.

sum+ = temp%10;

Here, we need to understand few things.

First, individual digits from given number is getting extracted using temp%10.

As in case of 18, the first extracted number using temp%10 will be 8.

Then, this number will get added to the variable sum.

At last, second number using temp%10 will be 1 and it will also be added to sum.

Now, sum is containing 8+1 = 9

temp/=10;

In previous operation, we have seen that the first extracted number using temp%10 was 8. Immediately, after this operation, temp/=10; will be executed which means 18 is now going to be divided by 10 resulting to 1.8. This operation will permanently delete this 8 from temp variable. so that in next iteration, 8 doesn't gets added to the sum variable again. Like this, it will keep on deleting the digits from temp variable.

Here is the final outcome:

sum is now containing sum of digits i.e. 1+8 = 9

n is containing 18

Finally, with the conditional statement using if-else, it is determined if n mod(%) sum is equal to 0 or not as it can be seen in the program. If n mod(%) sum is equal to 0, then it is displaying that the number is a NIVEN number. Otherwise, it is displaying that the number is not a NIVEN number.

Now, write this program and test it with various numbers and increase your knowledge.

Happy Coding.......

SPY Number ICSE Computer Science

 

A number is called SPY if the sum of the digits equals the product of the digits.

Example:

123 is a SPY number

1+2+3 = 6

1*2*3 = 6

Let's start the code of determining if a number is SPY or not.

Below is the code for determining if a number is SUPERSPY.

import java.util.Scanner;

class SPY

{

    public static void main(String[]args)

    {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a number");

        int n = sc.nextInt();

        int sum = 0,temp = n, mul = 1;

        while(temp!=0)

        {

            sum+=temp%10;

            mul*=temp%10;

            temp/=10;

        }

        if(sum == mul)

        {

            System.out.println("It is a SPY number");

        }

        else

        {

            System.out.println("It is not a SPY number");

        }

    }

}

Demonstration:

1. First, Scanner class is imported.
2. A class namely SPY have been defined.
3. A main method have been defined.
4. Object of Scanner class have been created.
5. A Number has been demanded from user by giving a message.
6. To accept and store the number, a variable namely n has been defined of int data type

7. Then, three different variables namely

    a) sum - This variable will store the sum of digits. First, it is initialized with 0.

    b) temp - This variable will hold the number given by user on temporary basis. Actually, entire operation will be done with temp variable. temp = n means the value stored in n namely variable is getting assigned to temp. It means that throughout the entire operation, original value stored in n namely variable will remain safe.

    c) mul - This variable will store the sum of digits. First, it is initialized with 1.

Now, let us see the working:

while(temp!=0)

This loop will continue its iteration until value of temp doesn't become equals to 0. Say for example, user gave 123. Here, first 3 will be extracted, then 2 and at last, 1 will get extracted as it is in index 0. Refer to the below diagram for clear understanding.

sum+ = temp%10;

Here, we need to understand few things.

First, individual digits from given number is getting extracted using temp%10.

As in case of 123, the first extracted number using temp%10 will be 3.

Then, this number will get added to the variable sum.

Similarly, second number using temp%10 will be 2 and it will also be added to sum.

At last, third number using temp%10 will be 1 and it will also be added to sum.

Now, sum is containing 3+2+1 = 6

Next operation is mul* = temp%10;

Here, again we need to understand few things.

First, individual digits from given number is getting extracted using temp%10.

As in case of 123, the first extracted number using temp%10 will be 3.

Then, this number will get multiply by the variable mul.

Similarly, second number using temp%10 will be 2 and it will also get multiply by the variable mul.

At last, third number using temp%10 will be 1 and it will also get multiply by the variable mul.

Now, mul is containing 3*2*1 = 6

temp/=10;

In previous operations, we have seen that the first extracted number using temp%10 was 3. Immediately, after these operations, temp/=10; will be executed which means 123 is now going to be divided by 10 resulting to 12.3. This operation will permanently delete this 3 from temp variable. so that in next iteration, 3 doesn't gets added to the sum variable again. Like this, it will keep on deleting the digits from temp variable.

Here is the final outcome:

sum is now containing sum of digits i.e. 1+2+3 = 6

mul is now containing product of digits i..e 1*2*3 = 6

Finally, with the conditional statement using if-else, it is determined if sum is equal to mul or not as it can be seen in the program. If sum is equal to mul, then it is displaying that the number is a SPY number. Otherwise, it is displaying that the number is not a SPY number.

Now, write this program and test it with various numbers and increase your knowledge.

Happy Coding.......