和为s的连续子序列---双指针

import java.util.ArrayList;
public class Solution {
    public ArrayList<ArrayList<Integer> > FindContinuousSequence(int sum) {
       ArrayList<ArrayList<Integer>> res=new ArrayList<ArrayList<Integer>> ();
  
       if(sum==0)return res;
        int left=1;
        int right=2;
        while(left<right){
            int cur=(left+right)*(right-left+1)/2;
            if(cur==sum){
                ArrayList<Integer> l=new ArrayList<>();
                for(int i=left;i<=right;i++){
                    l.add(i);
                }
                res.add(l);
                left++;
            }else if(cur>sum){
                left++;
            }else{
                right++;
            }
        }
        return res;
    }
}