Download public class ICSE { void primeFactors()throws IOException

import java.io.*;
public class ICSE
{
void primeFactors()throws IOException
{ BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
for(int n=1; n<=20; n++)//to make the program work for 20 numbers
{ System.out.println("Enter a number");
int num=Integer.parseInt(br.readLine());
for(int i=1; i<=num; i++)
{ if(num%i==0) // check if i is a factor
{ int count=0;
//check if i is prime
for(int j=1; j<=i; j++)
{ if(i%j==0)
{ count++;
}
}//for j
if(count==2)
{ System.out.println(i);
}//if count
}//if n%i
}//for i
}//for n
}//primeFactors()
void palindromes()throws IOException
{ BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
for(int n=1; n<=20; n++)//to make the program work for 20 words
{ System.out.println("Enter a string");
String str=br.readLine();
String reverse="";
for(int i=str.length()-1; i>=0; i--)//read the string backwards
{ char c=str.charAt(i);
reverse=reverse+c;
}
if(str.equalsIgnoreCase(reverse))
{ System.out.println(str+" is a palindrome");
}
else
{ System.out.println(str+" is not a palindrome");
}
}//for n
}//vowels()
public static void main(String args[])throws IOException
{ BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
ICSE obj=new ICSE();
int choice=0;
do
{ System.out.println("1. Display prime factors for 20 numbers");
System.out.println("2. Check palindromes for 20 words");
System.out.println("3. Exit Program");
System.out.println("Enter choice");
choice=Integer.parseInt(br.readLine());
switch(choice)
{ case 1: obj.primeFactors();
break;
case 2: obj.palindromes();
break;
case 3: System.out.println("Quitting program");
break;
default: System.out.println("Wrong choice");
}//switch
}while(choice!=3);
System.out.println("Thanks");
}//main
}//class