【LeetCode】Triangle

class Solution {
public:
    int minimumTotal(vector<vector<int> > &triangle) {
        if (triangle.size() == 0)
		return 0;
	vector<int> f(triangle[triangle.size() - 1].size());
	f[0] = triangle[0][0];
	for (int i = 1; i < triangle.size(); i++)
	{
		for (int j = triangle[i].size() - 1; j >= 0; j--)
		{
			if (j == 0)
			{
				f[j] = f[j] + triangle[i][j];
			}
			else if (j == triangle[i].size() - 1)
			{
				f[j] = f[j - 1] + triangle[i][j];
			}
			else
			{
				f[j] = min(f[j - 1], f[j]) + triangle[i][j];
			}
		}
	}
	int ret = INT_MAX;
	for (int i = 0; i < f.size(); i++)
	{
		ret = min(ret, f[i]);
	}
	return ret;
    }
};