public static int[] numtwo(int[] params,int sum){
Map<Integer,Integer> hashtable=new HashMap<>();
for(int i=0;i<params.length;++i){
if(hashtable.containsKey(sum-params[i])){
return new int[]{hashtable.get(sum-params[i]),i};
}
hashtable.put(params[i],i);
}
return new int[0];
}