Python - 确定矩阵单元格是一个组

Question

给定一组代表矩阵中位置的元组。

for example {(1, 2), (1, 3), (2, 2), (0, 3), (0, 4)}

其中元组（r，k）表示行r和列k。 我怎样才能确定它们是否挂在一起？

examples 
{(1, 2), (1, 3), (2, 2), (0, 3), (0, 4)} => hangs together
{(1, 2), (1, 4), (2, 2), (0, 3), (0, 4)} => doesnt hang together

Answer 1

我只是做简单的BFS或DFS，例如：

def connected(cells):
    if cells:
        cells = cells.copy()
        stack = [cells.pop()]
        while stack:
            i, j = stack.pop()
            neighbors = {(i-1, j), (i+1, j), (i, j-1), (i, j+1)} & cells
            stack.extend(neighbors)
            cells -= neighbors
    return not cells

用法/演示：

for cells in ({(1, 2), (1, 3), (2, 2), (0, 3), (0, 4)},
              {(1, 2), (1, 4), (2, 2), (0, 3), (0, 4)}):
    print(connected(cells))

打印：

True
False