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) { if(triangle.size()==0) return 0; vector<int> f(triangle[triangle.size()-1].size()); f[0]=triangle[0][0]; for(int i=1;i<triangle.size();i++){ for(int j=triangle[i].size()-1;j>=0;j--){ if(j==0) f[j]=f[j]+triangle[i][j]; else if(j==triangle[i].size()-1) f[j]=f[j-1]+triangle[i][j]; else f[j]=min(f[j],f[j-1])+triangle[i][j]; } } int m=INT_MAX; for(int i=0;i<f.size();i++){ m=min(m,f[i]); } return m; } };
原文：http://www.cnblogs.com/li303491/p/4078910.html