LeetCode--Triangle

标签：leetcode   动态规划   

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).

Note:
Bonus point if you are able to do this using only O(n) extra space, where n is the total number of rows in the triangle.

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

LeetCode--Triangle

标签：leetcode   动态规划   

原文地址：http://blog.csdn.net/shaya118/article/details/42718009