multidimensional-array - 如何在菱形等轴测图中从后到前迭代

Question

想象一个菱形等距图，它基本上是一个以 (x,y) 坐标和顶部单元格为原点的二维数组，如单元格中所标记:



我想按以下顺序从后到前遍历这些单元格:



通过未知的同侧 map 以这种方式循环的算法是什么？

预期输出:[0,0]、[0,1]、[1,0]、[0,2]、[1,1]、[2,0]、[0,3]等

Answer 1

python 伪代码:

def iterate_cells(n):
    for i in range(n):
        for j in range(i+1):
            yield (j, i-j)
    for i in range(1, n+1):
        for j in range(n - i):
            yield(i+j, n-j-1)

输出:

In [119]: list(iterate_cells(5))
Out[119]: 
[(0, 0),
 (0, 1),
 (1, 0),
 (0, 2),
 (1, 1),
 (2, 0),
 (0, 3),
 (1, 2),
 (2, 1),
 (3, 0),
 (0, 4),
 (1, 3),
 (2, 2),
 (3, 1),
 (4, 0),
 (1, 4),
 (2, 3),
 (3, 2),
 (4, 1),
 (2, 4),
 (3, 3),
 (4, 2),
 (3, 4),
 (4, 3),
 (4, 4)]