Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.
For example, given the following triangle
[[2],[3,4], [6,5,7], [4,1,8,3]]
The minimum path sum from top to bottom is11(i.e.,2+3+5+1= 11).
Note:Bonus point if you are able to do this using onlyO(n) extra space, wherenis the total number of rows in the triangle.
题意：数塔求最小的路径和是多少。
思路：数塔的DP思想，为了不妨碍后面的计算，我们每行计算从后面开始。
public class Solution {public int minimumTotal(List<List<Integer>> triangle) {int n = triangle.size();if (n == 0) return 0;int f[] = new int[triangle.size()];f[0]= triangle.get(0).get(0);for (int i = 1; i < triangle.size(); i++)for (int j = triangle.get(i).size()-1; j >= 0; j–) {if (j == 0)f[j] = f[j] + triangle.get(i).get(j);else if (j == triangle.get(i).size() – 1)f[j] = f[j-1] + triangle.get(i).get(j);else f[j] = Math.min(f[j-1], f[j]) + triangle.get(i).get(j);}int ans = Integer.MAX_VALUE;for (int i = 0; i < f.length; i++)ans = Math.min(ans, f[i]);return ans;}}
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趁着有脾气装潇洒，有本钱耍个性，
