数字三角形

代码：

class Solution {

public:

    /**

     * @param triangle: a list of lists of integers.

     * @return: An integer, minimum path sum.

     */

    int minimumTotal(vector<vector<int> > &triangle) {

        // write your code here

        const int len = triangle.size();

        vector<vector<int>> buff(len, vector<int>(len));

        buff[0][0] = triangle[0][0];

        for (int i = 1; i < len; i++)

        {

            for (int j = 0; j <= i; j++)

            {

                // 要取buff[i-1][j-1]，和buff[i-1][j]，但是要保证不越界。

                // 第i-1行的j的取值范围为[0, i-1]

                int lo = max(0, j-1);

                int hi = min(j, i-1);

                buff[i][j] = min(buff[i-1][lo], buff[i-1][hi]) + triangle[i][j];

            }

        }

        int res = buff[len-1][0];

        for (int i = 1; i < len; i++)

            res = min(res, buff[len-1][i]);

        return res;

    }

};

lintcode截图：