Twin Prime Number in a range

 

import java.io.*; 

import java.util.*;

 

public class Main

{static boolean checkPrimeNumber(int number) 

    { 

        int i; 

        int m = 0; 

        int flag = 0;       

        m = number/2;       

        if(number == 0 || number == 1){   

            return false;       

        }else{   

            for(i = 2; i <= m ;i++){       

                if(number%i == 0){       

                    flag=1;       

                    return false;       

                }       

            }       

            if(flag == 0)   

            {  

                return true; 

            }   

        } 

        return false; 

    }     

    static boolean checkTwinPrimeNumber(int number1, int number2) 

    { 

        if(checkPrimeNumber(number1) && checkPrimeNumber(number2) && Math.abs(number1 - number2) == 2) 

            return true; 

        else 

            return false; 

    } 

  

    public static void main(String[] args) 

    { 

        int startRange, endRange; 

         

        Scanner sc=new Scanner(System.in);          

      

        System.out.println("Enter start value");            

        startRange = sc.nextInt();            

                System.out.println("Enter last value");            

        endRange = sc.nextInt(); 

         

        System.out.println("The pairs of twin primes between" + startRange + " and " + endRange + "are:"); 

         

        for (int i = startRange; i < endRange; i++) { 

            if (checkTwinPrimeNumber(i, (i + 2))){ 

                System.out.printf("(%d, %d)\n", i, i + 2); 

            } 

        } 

    } 

} 

Neon Number

 import java.util.Scanner;  

import java.lang.Math;  

public class Main

{

    

public static void main(String args[])     

{     

int sum = 0, n;      

Scanner sc = new Scanner(System.in);  

System.out.print("Enter the number to check: ");  

n = sc.nextInt();  

int square = n * n; 

while(square != 0)  

{  

 

int digit = square % 10; 

sum = sum + digit;

square = square / 10;  

}  

if(n == sum)  

System.out.println(n + " is a Neon Number.");  

else  

System.out.println(n + " is not a Neon Number.");  

}  

}  

DecimalToBinary

 

import java.util.Scanner; 

import java.lang.Math; 

public class Main

{

    public static int convertDecimalToBinary(int dec) {

   

      int rem,b1=0;

      int rev = 1;

      while (dec > 0) {

         rem = dec % 2;

         dec = dec / 2;

         b1 = b1 + rem * rev;

         rev = rev * 10;

      }

    return b1;

  }

public static void main(String args[])    

{    

 

 

    Scanner in = new Scanner(System.in); 

System.out.print("Enter a number : "); 

 

int num = in.nextInt(); 

 

    int decimal = convertDecimalToBinary(num);

    System.out.println("Binary to Decimal");

    System.out.println(num + " = " + decimal);

  }

 

 

}

Automorphic Number

 

import java.util.Scanner; 

import java.lang.Math; 

public class Main

{

public static void main(String args[])    

{    

Scanner in = new Scanner(System.in); 

System.out.print("Enter a number to check: "); 

 

int num = in.nextInt(); 

int count=0;

int square = num*num;

int temp = num;

while(temp>0) 

{ 

count++;

temp=temp/10; 

}  

int lastDigit = (int) (square%(Math.pow(10, count)));  

if(num == lastDigit) 

System.out.println(num+ " is an automorphic number."); 

else 

System.out.println(num+ " is not an automorphic number."); 

} 

} 

Armstrong Number

 

import java.util.Scanner; 

import java.lang.Math; 

public class Main

{

     static boolean isArmstrong(int n)  

{  

int temp, digits=0, last=0, sum=0;  

 

temp=n;  

 

while(temp>0)   

{  

temp = temp/10;  

digits++;  

}  

temp = n;  

while(temp>0)  

{

last = temp % 10;  

sum +=  (Math.pow(last, digits));

temp = temp/10;  

} 

 

if(n==sum)

return true;

else return false;  

}  

   

   

 

public static void main(String args[])    

{    

int num;  

Scanner sc= new Scanner(System.in); 

System.out.print("Enter the limit: ");

num=sc.nextInt(); 

if(isArmstrong(num)) 

System.out.print(num+ " is armstrong Number "); 

}  

} 

Fibonacci series

 

import java.util.*;

 

public class Main

{

                public static void main(String[] args) {

                        Scanner sc = new Scanner(System.in); 

                                 System.out.println( " enter a value");

 

                     int n1=0,n2=1,n3,i,count;

                     count = sc.nextInt();   

 

   

 for(i=1;i<=count;++i)//loop starts from 2 because 0 and 1 are already printed   

 {   

  n3=n1+n2;   

  System.out.print(" "+n1);   

  n1=n2;   

  n2=n3;   

 }   

 

}} 

 

Java happy Number

 

import java.util.*;

public class Main

{public static int isHappyNumber(int num){ 

        int rem = 0, sum = 0; 

         

        while(num > 0){ 

            rem = num%10; 

            sum = sum + (rem*rem); 

            num = num/10; 

        } 

        return sum; 

    } 

                public static void main(String[] args) {

                    Scanner sc = new Scanner(System.in); 

                                 System.out.println( " enter a value");

                                 int num = sc.nextInt();   

        int result = num; 

         

        while(result != 1 && result != 4){ 

            result = isHappyNumber(result); 

        } 

         

      

        if(result == 1) 

            System.out.println(num + " is a happy number"); 

        else if(result == 4) 

            System.out.println(num + " is not a happy number");    

    } 

} 

Java Magic Number

 

import java.util.Scanner; 

public class Main

{

                public static void main(String[] args) {

                                int n, remainder = 1, number, sum = 0; 

Scanner sc = new Scanner(System.in); 

System.out.print("Enter a number you want to check: "); 

n = sc.nextInt(); 

number = n; 

while (number > 9)               

{ 

while (number > 0) 

{ 

remainder = number % 10;  

sum = sum + remainder; 

number = number / 10;    

} 

number = sum; 

sum = 0; 

} 

if (number == 1) 

{ 

System.out.println("The given number is a magic number."); 

} 

else 

{ 

System.out.println("The given number is not a magic number."); 

} 

} 

} 

Write a program to accept a word from the user . Print the converted word where the consonants are upgraded by nearest vowel and vowels are upgraded to nearest consonant.

 import java.util.Scanner;

import java.util.Random;

public class Main

{

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.print("Enter a word: ");

String word = scanner.nextLine();

scanner.close();

String convertedWord = convertWord(word);

System.out.println("Converted word: " + convertedWord);

}

private static String convertWord(String word)

{

StringBuilder converted = new StringBuilder();

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

{char convertedChar;

    

char c = word.charAt(i);

if (c!=' '){

 convertedChar = convertCharacter(c);}else{convertedChar =' ';}

converted.append(convertedChar);

}

return converted.toString();

} 

private static char convertCharacter(char c)

{

if (isVowel(c))

{

return findNearestConsonant(c);

}

else

{

return findNearestVowel(c);

}

}

private static boolean isVowel(char c)

{

c = Character.toLowerCase(c);

return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';

}

private static char findNearestConsonant(char c)

{

while (true)

{

c--;

if (!isVowel(c))

{

return c;

}

}

} 

private static char findNearestVowel(char c)

{

while (true)

{

c++;

if (isVowel(c))

{

return c;

}

}

}

}

Write a program to accept a string from user and display the words that are having repeating characters.

 import java.util.Scanner;

import java.util.Random;

public class Main

{

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

System.out.print("Enter a string: ");

String inputString = scanner.nextLine();

String[] words = inputString.split(" ");

System.out.println("Words with repeating characters:");

for (String word : words)

{

    if (hasRepeatingCharacters(word))

    {

        System.out.println(word);

    }

}

scanner.close();

}

private static boolean hasRepeatingCharacters(String word)

{

    for (int I = 0; I < word.length() - 1; I++)

    {

        char currentChar = word.charAt(I);

        for (int j = I + 1; j < word.length(); j++)

        {

            if (currentChar == word.charAt(j))

            {

                return true;

            }

        }

    }

        return false;

}

   

}

Enter a string: bbn bnb vbn xcdxx

Words with repeating characters:

bbn

bnb

xcdxx