两数之和
public ArrayList<Integer> FindNumbersWithSum(int [] array,int sum) {

    ArrayList<Integer> result = new ArrayList();
    
    if(array == null || array.length == 1){
        return result;
    }
    
    int left = 0;
    int right = array.length-1;
    while(left < right){
        if(array[left]+array[right] == sum){
            result.add(array[left]);
            result.add(array[right]);
            return result;
        }
        
        if(array[left] + array[right] < sum){
            left++;
        }else{
            right--;
        }
    }
    return result;
}