/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		int[] arr = {2,3,4,1,1,2,4};
		findOdd(arr);
	}
 
	public static void findOdd(int[] arr){
		HashMap hm = new HashMap();
		int value=0;
		for(int i=0;i<arr.length;i++){
			value=1;
			if(hm.containsKey(arr[i])){
				value = (Integer) hm.get(arr[i]);
				value++;
			}
			hm.put(arr[i], value);
		}
 
		Iterator it = hm.entrySet().iterator();
		Map.Entry entry=null;
		while(it.hasNext()){
			entry = (Map.Entry)it.next();
			if((Integer)(entry.getValue())%2!=0){
				System.out.println((Integer)entry.getKey() +" has occurred odd no of time");
			}
		}
 
	}
}

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