Hashmaps:Pair Sum to 0

import java.util.HashMap;
public class Solution {
    public static void PairSum(int[] input, int size) {
        if(size==0)
            return;
        HashMap<Integer,Integer> h=new HashMap<>();
        for(int i=0;i<size;i++)
        {   
            if(h.containsKey(-input[i]) && h.get(-input[i])!=0){
                int count=h.get(-input[i]);
                
                while(count!=0)
                {   if(input[i]>0)
                    System.out.println(-input[i] +" "+ input[i]);
                 else
                     System.out.println(input[i] +" "+( -input[i]));
                 count--;
                }
                if(h.containsKey(input[i]))
                    h.put(input[i],h.get(input[i])+1);
                else
                    h.put(input[i],1);
            }
            else{
                if(h.containsKey(input[i])){
                    h.put(input[i],h.get(input[i])+1);
                }else{
                    h.put(input[i] ,1);
                }
            }


        }

    }
}