Duplicate Char Display

package interview;

import java.util.*;

public class DuplicateCharDisplay {

public static void main(String[] args)
{
  String str = "welcome to apple world";
  displayDuplicate(str);

}

private static void displayDuplicate(String str)
{
  Map <Character,Integer> map = new HashMap<>();
  char  [] ch = str.toCharArray();
  for(char c : ch)
  {
  if(!map.containsKey(c))
  {
  map.put(c, 1);
  }
  else
  {
map.put(c, map.get(c)+1); 
  }
  }
  // Now Iterate map
  /*for(char c : map.keySet())
  {
  System.out.println(c +" - "+map.get(c));
  }*/
 
  for(Map.Entry<Character,Integer> entry : map.entrySet())
{
    if(entry.getValue()>1)
    {
System.out.printf("%s : %d %n",entry.getKey(),entry.getValue());
    }
}
}

}

Duplicate Strings

package interview;
import java.util.*;
public class DuplicateStrings
{
//String-->String.split()--->String[]--->Uppercase--->Hashmap
public static void main(String[] args)
{
  String str = "This is what is this world in world 45 67 45";
  String[] str2 = str.split(" ");
  String[] str3 = toUpperString(str2);
  show(str3);
 
  Map<String,Integer> map = new HashMap<>();
  for(String s : str3)
  {
  if(map.containsKey(s))
  {
  map.put(s,map.get(s)+1);
  }
  else
  {
  map.put(s, 1);
  }
  }
//*****************************
  for(Map.Entry<String,Integer> entry : map.entrySet())
  {
  if(entry.getValue()>1)
  {
  System.out.println(entry.getKey()+" --->"+entry.getValue());
  }
  }
 
}

    private static void show(String[] str3)
    {
  for(String s : str3)
  System.out.print(s+" ");
  System.out.println("");
    }

private static String[] toUpperString(String[] str2)
     {
for(int i =0;i<str2.length;i++)
{
str2[i] = str2[i].toUpperCase();
}
    return str2;
     }

}

Fibonacci

package interview;

public class Fibonacci {

public static void main(String[] args)
{
  int fib1 = 0;
  int fib2 = 1;  
  int fib3;
  int limit = 10;
  System.out.println("First "+limit+" terms");
  for(int i = 1; i<limit;++i)
  {
  System.out.println(fib1);
  fib3 = fib1+ fib2;
  fib1 = fib2;
  fib2 = fib3;
  }

}

}

First Non Repeated Character

package interview;

import java.util.*;

//Print first Non Repeated character
public class FirstNonRepeatedCharacter {

public static void main(String[] args)
{
  String str = "computercomputes";
  char[] ch = str.toCharArray();
  LinkedHashMap<Character,Integer> link = new LinkedHashMap<>();
  for(int i = 0;i<ch.length;i++)
  {
  if(link.containsKey(ch[i]))
  {
  link.put(ch[i], link.get(ch[i])+1);
  }
  else
  {
  link.put(ch[i],1);
  }
  }
  //***Iterate
  for(Map.Entry<Character,Integer> entry : link.entrySet())
  {
  if(entry.getValue()==1)
  {
  System.out.println("first NRC: "+entry.getKey());
  System.out.println("first NRC: "+entry.getKey().toString().toUpperCase());
  return;
  }
  }
 
 

}

}

Palindrom_Num

package interview;

public class Palindrom_Num {
//reverse karke check kar lo
public static void main(String[] args)
{
  int a = 121;
  int t = a;
  int rev=0;
  int temp = 0;
  while(a>0)
  {
  temp = a%10;
  rev = (rev*10)+temp;
  a= a/10;  
  }
  if(t == rev)
  System.out.println("Palindrom");
  else
  System.out.println("Not Palindrom");
 
 
//Method 2: Starts ***********************************************
int num2 = 1210121;  
   StringBuffer sb7 = new StringBuffer(num2);
   if(sb7==sb7.reverse())
   System.out.println(num2+" : is Pelindrom");
   else
   System.out.println(num2+" : is Not Pelindrom");
 //Method 2 :Ends ***********************************************
}



}

Prime Numbers

package interview;

public class Prime {

public static void main(String[] args)
{
  boolean flag = false;
  int num = 127;
  for(int i = 2;i<Math.sqrt(num)+1;i++)
  {
  if(num%i == 0)
  {
   flag = true;
  }
  }
         System.out.println(flag ==  true ? Not Prime : Prime);

}

}

Reverse_Each_Word

package interview;

public class Reverse_Each_Word
{

public static void main(String[] args)
{
String s1 = "java programming uses JVM";
String[] s2 = s1.split(" ");  //[java , programming]
String rev = "";
for(int i = 0;i<s2.length;i++)
{
  String s = s2[i]; //java
 
for(int j =s.length()-1; j>=0 ;j--)
{
rev = rev + s.charAt(j);
}
rev= rev +" ";
}
System.out.println("Original: "+s1);
System.out.println("Reversed: "+rev);


}
}