和为S的连续正数序列

class Solution {
public:
    vector<vector<int> > FindContinuousSequence(int sum) {
        vector<vector<int> > res;
        int left = 1;
        int right = 2;
        while(left<right){
            int curSum = (right+left)/2*(right-left+1);
            if(curSum == sum){
                vector<int> tmp;
                for(int i = left; i <= right; i++){
                    tmp.push_back(i);
                }
                res.push_back(tmp);
                left++;
            }
            else if(curSum < sum){
                right++;
            }
            else{
                left++;
            }
        }
        return res;
    }
};