C++等差数列

class Solution {
public:
    //S=n(a1+a2)/2
    vector<vector<int> > FindContinuousSequence(int sum) {
        vector<vector<int>> ans;
        int &s = sum;

        int up = sum-1;
        int n = up;
        while(n>=2)
        {
            int a1 = ((((2*s - n*n + n)%(2*n))%(2*n))==0)?((((2*s - n*n + n)/(2*n)))):-1;
            if(a1!=-1&&a1>0)
            {
                vector<int> temp;
                for(int i=a1;i<a1+n;i++)
                    temp.push_back(i);
                ans.push_back(temp);
            }   

            --n;
        }
        return ans;
    }
};