120. Triangle

        这道题是说求从三角形顶端到低端路径数字之和的最小值，我的想法是两个数组分别表示上一行和当前行，计算两层的和，以此类推，最后一行的时候找到最小值即为所求。

class Solution {public:int minimumTotal(vector<vector<int>>& triangle) {int m = triangle.size();if (m == 1) return triangle[0][0];vector<int> l = triangle[0];vector<int> h = triangle[1];int MIN;for (int j = 1;j < m;) {int n = triangle[j].size();for (int i = 0;i < n;i++) {if (i == 0) h[i] += l[i];else if (i == n - 1) h[i] += l[i - 1];else h[i] = h[i] + min(l[i], l[i - 1]);}l = h;if (j == m - 1) break;h = triangle[++j];}MIN = l[0];for (int t : l) {if (MIN > t) MIN = t;}return MIN;}};