public int TwoSumProblem() {
		int x, y = 0;
		int count = 0;
		LinkedList<Integer> sums = new LinkedList<Integer>();
		// sum between [2500,4000]
		for (int sum = 2500; sum <= 4000; sum++) {
			for (int i = 0; i < arrayLen; i++) {
				x = originalArray[i];
				y = sum - x;
				if (x == 0 || x == y)
					continue;
				if (IsExistInHashMap(y)) {
					sums.add(sum);
					count++;
					//System.out.println(x + "," + y + "=" + sum);
					break;
				}
			}
		}

		// Iterator<Integer> i = sums.iterator();
		// while (i.hasNext()) {
		// System.out.print(i.next() + " ");
		// }
		// System.out.println();
		return count;
	}