和为S的两个数字

public class Solution {

    public ArrayList FindNumbersWithSum(int [] array,int sum) {

        ArrayList<Integer> list = new ArrayList<>();

        if (array == null || array.length < 2) {

            return list;

        }

        int i = 0;

        int j = array.length - 1;

        while (i < j) {

            if(array[i] + array[j] == sum){ //先取数组的第一个和最后一个数字相加

                list.add(array[i]);

                list.add(array[j]);

                return list;

            }

            else if(array[i] + array[j] > sum) //根据sum调整i和j

                j--;

            else

                i++;

        }

        return list;

    }

}