A prime palindrome integer

A prime palindrome integer is a positive integer (without leading zeros) which is prime as well as a palindrome. Given two positive integers m and n, where m < n, write a program to determine how many prime-palindrome integers are there in the range between m and n (both inclusive) and output them.

The input contains two positive integers m and n where m < 3000 and n < 3000. Display the number of prime-palindrome integers in the specified range along with their values in the format specified below:

Test your program with the sample data and some random data:

Example 1

INPUT:

m = 100

n = 1000

OUTPUT:

THE PRIME PALINDROME INTEGERS ARE:

101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 757, 787, 797, 919, 929

FREQUENCY OF PRIME PALINDROME INTEGERS : 15

Example 2

INPUT:

m = 100

n = 5000

OUTPUT: OUT OF RANGE

Solution:

/*

[Printing all the Prime palindrome numbers in the given range]

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*/

import java.io.*;

class PalPrime

{

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

/* Function isPrime( ) returns 'true' when the number 'x' is Prime and 'false' if it is not. */

boolean isPrime(int x)

{

int count=0;

for(int i=1;i<=x;i++)

{

if(x%i==0)

count++;

}

if(count==2)

return true;

else

return false;

}

/*Function isPalin( ) returns 'true' when 'x' is a Palindrome and 'false' if it is not.*/

boolean isPalin(int x)

{

int rev=0,dig;

int copy=x;

while(x>0)

{

dig=x%10;

rev=rev*10+dig;

x=x/10;

}

if(rev==copy)

return true;

else

return false;

}

/* Function showPalPrime( ) accepts the lower and upper limit, and prints all the PalPrime numbers in between that range by sending each numbers in the range to both the functions isPrime( ) and isPalin( ) */

public void showPalPrime() throws IOException

{

int m,n;

int c=0;

System.out.print("Enter the Lower Limit (m) = ");

m=Integer.parseInt(br.readLine());

System.out.print("Enter the Upper Limit (n) = ");

n=Integer.parseInt(br.readLine());

if(m>=n || m>=3000 || n>=3000)// Checking the range of Limits as given in the question

System.out.println("OUT OF RANGE");

else

{

System.out.println("\nThe Prime Palindrome integers are:");

/* The below for loop generates every number starting from 'm' till 'n' and sends it to both functions isPalin() and isPrime(), to check whether they are both Palindrome and prime or not. If yes, then they are printed. */

for(int i=m; i<=n; i++)

{

if(isPrime(i)==true && isPalin(i)==true)

{

if(c==0)

System.out.print(i); //Printing the first PalPrime number in order to maintain the sequence of giving a comma ',' before every next PalPrime number, as is given in the Sample Output.

else

System.out.print(", "+i);

c++; //Counting the number of PalPrime numbers by incrementing the counter

}

}

System.out.println("\n\nFrequency of Prime Palindrome integers: "+c);

}

}

/* The main method creates an object of PalPrime Class and calls the function showPalPrime( ) */

public static void main()throws IOException

{

PalPrime ob=new PalPrime();

ob.showPalPrime();

}

}