Minimum Path Sum

Given a_m_x_n_grid filled with non-negative numbers, find a path from top left to bottom right which_minimizes_the sum of all numbers along its path.

Note:You can only move either down or right at any point in time.

Example:

Input:
[
  [1,3,1],
  [1,5,1],
  [4,2,1]
]
Output: 7
Explanation: Because the path 1→3→1→1→1 minimizes the sum.

Solution

class Solution {
    public int minPathSum(int[][] grid) {

    }
}