筆試題：求和爲sum的連續數列

#include <iostream>
#include <vector>
using namespace std;
class Solution {
public:
	vector<vector<int> > FindContinuousSequence(int sum){
		int index;
		//思想：
		//(y-x+1)=n;
		//(x+y)*n/2=sum;
		//--->(2*x-1+n)=2*sum/n;
		//--->2xn=2*sum-n*n+n;
		//--->x=(2*sum-n*n+n)/(2*n);
		//由以上推導公式可以得出下面的正確結論。
		vector<vector<int>> v1;
		vector<int> v2;
		for (int i = sum; i >= 1; --i)
		{
			int x = 2 * i;
			int y = 2*sum + i - i*i;

			if (y>0)
			{
				if (y%x == 0)
				{
					int m = 0;
					index = y / x;
					while (m<i)
					{
						v2.push_back(m + index);
						m++;
					}
					v1.push_back(v2);
					v2.clear();
				}
			}
		}
		return v1;
	}
};
int main()
{
	Solution sl;
	vector<vector<int>> v = sl.FindContinuousSequence(300);
	for (int i = 0; i < v.size(); i++)
	{
		for (int j = 0; j < v[i].size(); j++)
		{
			cout << v[i][j] << " ";
		}
		cout << endl;
	}
	return 0;
}