下雨积水问题

int Adjust(stack<int> & s, int const cur, vector<int> const & L)
{
	int sum = 0;
	while (!s.empty() && L[cur] > L[s.top()])
	{
		int top = L[s.top()];
		s.pop();
		if (!s.empty())
		{
			sum += (min(L[s.top()], L[cur]) - top)*(cur - s.top() - 1);
		}
	}
	s.push(cur);
	return sum;
}
int Sum(vector<int> const& L)
{
	int sum = 0;
	stack<int> s;
	int const size = L.size();
	for (int i = 0; i < size - 1; ++i)
	{
		if (L[i] < L[i + 1] && !s.empty())
		{
			sum += (i - s.top()) * (min(L[s.top()], L[i + 1]) - L[i]);
		}
		else if (L[i] >L[i + 1])
		{
			sum += Adjust(s, i, L);
		}
	}
	sum += Adjust(s, size - 1, L);
	return sum;
}

int main(int argc, char* argv[])
{
	vector<vector<int>> testCase
	{
		{ 2, 5, 1, 2, 3, 4, 7, 7, 6 },
		{6,7,7,4,3,2,1,5,2},
		{1,7,4,1,2,4,2,7,1},
		{1,7,4,11,0,11,2,4,2,7,1},
		{ 11, 0, 7, 0, 5, 0, 3, 0, 1 },
		{5,0,2,4},
		{5, 0, 2, 5}
	};

	std::for_each(testCase.begin(), testCase.end(), [](vector<int> const &L){cout << Sum(L) << endl; });
	return 0;
}