LeetCode 64. Minimum Path Sum

public class Solution {
    public int minPathSum(int[][] grid) {
        int m = grid.length;
        int n = grid[0].length;
        for (int i = 0; i < m; i++) {
        	for (int j = 0; j < n; j++) {
        		if (i == 0 && j != 0) grid[i][j] += grid[i][j - 1];
        		if (i != 0 && j == 0) grid[i][j] += grid[i - 1][j];
        		if (i != 0 && j != 0) grid[i][j] += grid[i - 1][j] < grid[i][j - 1]
        				? grid[i - 1][j] : grid[i][j - 1];
        	}
        }
        return  grid[m - 1][n - 1];
    }
}