leetcode之Minimum Path Sum

这题跟unique path系列是一起的，主要还是从右下角的开始，一步一步的往左上算，能做出来之前的这个就非常简单。代码如下：

#m代表行，n代表列
        m = len(grid)
        n = len(grid[0])
        for i in range(m)[::-1]:
            for j in range(n)[::-1]:
                if i + 1 < m and j + 1 < n:
                    grid[i][j] += min(grid[i + 1][j], grid[i][j + 1])
                elif i + 1 >= m and j + 1 < n:
                    grid[i][j] += grid[i][j + 1]
                elif i + 1 < m and j + 1 >= n:
                    grid[i][j] += grid[i + 1][j]
                else:
                    pass
        return grid[0][0]