LeetCode:Triangle

标题叙述性说明：

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 is

11

(i.e., 2 + 3 + 5 + 1 =
11).

思路：经典的动态规划题目。

自底向上遍历给定的数组，依次算出每点究竟部的最短路径，当遍历到第一层时即得到结果。

代码：

int minimumTotal(vector<vector<int> > &triangle)
{
int length = triangle.size();
vector<int> min_total;
for(int i = 0;i < length;i++)
min_total.push_back(triangle[length-1][i]);
for(int i = length-2;i >= 0;i--)
for(int j = 0;j <= i;j++)
{
min_total[j] = min(min_total[j],min_total[j+1]) + triangle[i][j];
}
return min_total[0];
}