Menduplikat

Kodenya


import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class duplicate
 {

  public void countDupChars(String str){

    //Create a HashMap
    Map<Character, Integer> map = new HashMap<Character, Integer>();

    //Convert the String to char array
    char[] chars = str.toCharArray();

    /* logic: char are inserted as keys and their count
     * as values. If map contains the char already then
     * increase the value by 1
     */
    for(Character ch:chars){
      if(map.containsKey(ch)){
         map.put(ch, map.get(ch)+1);
      } else {
         map.put(ch, 1);
        }
    }

    //Obtaining set of keys
    Set<Character> keys = map.keySet();

    /* Display count of chars if it is
     * greater than 1. All duplicate chars would be
     * having value greater than 1.
     */
    for(Character ch:keys){
      if(map.get(ch) > 1){
        System.out.println("Char "+ch+" "+map.get(ch));
      }
    }
  }

  public static void main(String a[]){
    duplicate obj = new duplicate();
    System.out.println("String: BeginnersBook.com");
    System.out.println("-------------------------");
    obj.countDupChars("BeginnersBook.com");

    System.out.println("\nString: ChaitanyaSingh");
    System.out.println("-------------------------");
    obj.countDupChars("ChaitanyaSingh");

    System.out.println("\nString: #@$@!#$%!!%@");
    System.out.println("-------------------------");
    obj.countDupChars("#@$@!#$%!!%@");
  }
}

Hasilnya