public static void main(String args[]){ int[] arr = { 1, 2, 1, 2, 5, 6, 1, 2, 8, 9, 5, 6, 8, 9 }; Set<Pair> set = new HashSet<>(); for(int i = 0; i < arr.length-1; i+=2) { set.add(new Pair(arr[i], arr[i+1])); } String[][] arr2 = new String[set.size()][]; int i = 0; for(Pair p : set) { arr2[i] = p.toStringArr(); } //Unique pairs now in string array arr2. }