双指针

import java.util.ArrayList;
import java.util.*;
public class Solution {
    public ArrayList<Integer> FindNumbersWithSum(int [] array,int sum) {
        
        ArrayList<Integer> re= new ArrayList<>();
        
        int s;
        int i = 0;
        int j = array.length - 1;
        
        while(i < j){
            s = array[i] + array[j];
            if(s > sum){
                j--;
                
            }
            if(s < sum){
                i++;
            }
            if(s == sum){
                re.add(array[i]);
                re.add(array[j]);
                return re;
            }
                
        }
       
        return re;
        
    }
}