see-120. Triangle

动态规划: 

triangle[i][j]=min(triangle[i][j]+triangle[i+1][j],triangle[i][j]+triangle[i+1][j+1]);   

return triangle[0][0];

2                            2                                2                                   11

3 4                         3 4                             9  10                             9  10

6 5 7                      7 6 10                        7   6 10                         7   6 10

4 1 8 3                   4 1 8 3                       4   1   8  3                     4   1   8  3

class Solution {
public:
    int minimumTotal(vector<vector<int>>& triangle) {
        for(int i=triangle.size()-2;i>=0;i--)
            for(int j=0;j<=i;j++)
            {
                triangle[i][j]=min(triangle[i][j]+triangle[i+1][j],triangle[i][j]+triangle[i+1][j+1]);
            }
        return triangle[0][0];
    }
    int min(int a,int b)
    {
        return a<b?a:b;
    }
};