Question

鉴于此输入：

[2,2,2,1], [4,3,0,0]

输出：转换列表的步骤

Move 2 from C_to_A
Move 1 from D_to_B

为了方便起见，可以这种方式引用列表：

[A, B, C, D] #Just some means to reference the to and from of the move.

到目前为止我所拥有的：

    locations = {
        0: "A",
        1: "B",
        2: "C",
        3: "D"
    }

def get_steps_for_distribution(c, d):
    print 'current: {} desired: {}'.format(c, d)
    for i in range(0, len(c)):
        diff = c[i] - d[i]        
        while diff > 0:
            for j in range(1, len(c)):
                next_index = (i + j) % len(c)
                importer_diff = c[next_index] - d[next_index]
                if importer_diff < 0:
                    number_to_move = min(diff, (0 - importer_diff))
                    diff -= number_to_move
                    importer_diff += number_to_move
                    c[i] -= number_to_move
                    d[i] += number_to_move
                    print_move_line(number_to_move, i, next_index)

例如，给出了一个问题：

get_steps([2,2,2,1], [4,3,0,0])

目前它提供了将所有内容转移到位置A的步骤，从而产生了这一点，这不是所提供的第二个列表的准确表示。：

>>>Move 2 from C_to_A
>>>Move 0 from C_to_B
>>>Move 1 from D_to_A
>>>Move 0 from D_to_B

Answer 1

我找到了。问题是您没有更新需求（c）和资源（d）的主列表。在代码的底部，添加几行来实现这些更新：

               diff -= number_to_move
               importer_diff += number_to_move
               c[i] -= number_to_move
               d[i] += number_to_move

这会逐渐更新资源列表，直到它等于需求列表。

注意：一旦你开始工作，你可以改进一些事情：

变量名称：使它们更具描述性，并在“导出”和“导入”之间以及每个组内很好地对应。
使用模数：
简化 next_index 计算
next_index =（i + j）％len（c）
您无需更新 importer_diff ;无论如何，你在下一个循环中重新计算它。

我的解决方案

这会产生所需的输出：

locations = {
    0: "A",
    1: "B",
    2: "C",
    3: "D"
}

def print_move_line(number_to_move, exporter, importer):
    line = "Move " + str(number_to_move) + " from " + locations.get(exporter, "bad location") + "_to_" + locations.get(importer, "bad location")
    print line


def get_steps(have, want):
    for exporter_index in range(0, len(have)):
        diff = have[exporter_index] - want[exporter_index]

        # Move 'diff' units from bin 'exporter_index' to others;
        #   offer valid only while supplies last.
        while diff > 0:
            for j in range(1, len(have)):
                # Start next to the exporter and wrap around.
                importer_index = (exporter_index + j) % len(have)
                print("  DEBUG: have", have, "want", want, "\t", exporter_index, "to", importer_index)
                importer_diff = have[importer_index] - want[importer_index]

                # If this bin needs units, move what we have.
                if importer_diff < 0:
                    number_to_move = min(diff, (-importer_diff))
                    print("  DEBUG: bin", importer_index, "needs", importer_diff, "donor has", diff)
                    diff -= number_to_move
                    have[exporter_index] -= number_to_move
                    importer_diff -= number_to_move
                    have[importer_index] += number_to_move
                    print_move_line(number_to_move, exporter_index, importer_index)

get_steps([2, 2, 2, 1], [4, 3, 0, 0])

输出：

('  DEBUG: have', [2, 2, 2, 1], 'want', [4, 3, 0, 0], '\t', 2, 'to', 3)
('  DEBUG: have', [2, 2, 2, 1], 'want', [4, 3, 0, 0], '\t', 2, 'to', 0)
('  DEBUG: bin', 0, 'needs', -2, 'donor has', 2)
Move 2 from C_to_A
('  DEBUG: have', [2, 2, 4, 1], 'want', [2, 3, 0, 0], '\t', 2, 'to', 1)
('  DEBUG: bin', 1, 'needs', -1, 'donor has', 0)
Move 0 from C_to_B
('  DEBUG: have', [2, 2, 4, 1], 'want', [2, 3, 0, 0], '\t', 3, 'to', 0)
('  DEBUG: have', [2, 2, 4, 1], 'want', [2, 3, 0, 0], '\t', 3, 'to', 1)
('  DEBUG: bin', 1, 'needs', -1, 'donor has', 1)
Move 1 from D_to_B
('  DEBUG: have', [2, 2, 4, 2], 'want', [2, 2, 0, 0], '\t', 3, 'to', 2)
[wdwickar@wdwickar-ws pyside]$ python so.py
('  DEBUG: have', [2, 2, 2, 1], 'want', [4, 3, 0, 0], '\t', 2, 'to', 3)
('  DEBUG: have', [2, 2, 2, 1], 'want', [4, 3, 0, 0], '\t', 2, 'to', 0)
('  DEBUG: bin', 0, 'needs', -2, 'donor has', 2)
Move 2 from C_to_A
('  DEBUG: have', [4, 2, 0, 1], 'want', [4, 3, 0, 0], '\t', 2, 'to', 1)
('  DEBUG: bin', 1, 'needs', -1, 'donor has', 0)
Move 0 from C_to_B
('  DEBUG: have', [4, 2, 0, 1], 'want', [4, 3, 0, 0], '\t', 3, 'to', 0)
('  DEBUG: have', [4, 2, 0, 1], 'want', [4, 3, 0, 0], '\t', 3, 'to', 1)
('  DEBUG: bin', 1, 'needs', -1, 'donor has', 1)
Move 1 from D_to_B
('  DEBUG: have', [4, 3, 0, 0], 'want', [4, 3, 0, 0], '\t', 3, 'to', 2)

在python中，如何打印一个步骤列表，将整数列表转换为提供的第二个整数列表？

1 个答案: