Can you solve the Trojan War riddle? - Dennis E. Shasha

翻译人员: Fangyu Zhang 校对人员: Helen Chang

The Trojan War has been raging for 10 years,

特洛伊战争已经肆虐了十年

with neither Greeks nor Trojans prevailing.

希腊人和特洛伊人都没有占据上风

Gods and humans alike are desperate for a break,

上帝和人类都极度渴望休息

so when a divine omen races across the sky,

所以当天空中划过一道圣兆时

the two sides agree to a 10 day truce.

战争的双方达成共识，休战十天

From high up on Olympus you’ve been waiting for an opportunity

在高高的奥林匹斯山上，

你一直在等待一个 能够结束这场残酷战争的机会

to bring this bloody war to its conclusion.

When you go to consult the Fates, they advise:

你去向命运三女神求助，她们说道：

should the peace last for a full 10 days, all will end soon.

如果和平能够持续整整十天， 那么一切都会很快结束

However, if the truce is broken,

然而，如果休战被打断

the ensuing battle will lead to 10 more devastating years of war.

那么接下来将迎来十年 更具毁灭性的战争

The Fates’ loom has shown them the exact conditions

命运三女神的织布机显示 能够维持这次休战的具体条件

that will keep the truce intact.

The great Trojan plain can be viewed as a grid of Greek and Trojan encampments.

特洛伊大平原可被视为 希腊和特洛伊人营地的网格

If they’re organized in such a way that any Greek can reach any other Greek camp

如果网格的排布能使任何一个希腊人 可以不用经过特洛伊营地

without having to pass through a Trojan camp, and likewise for Trojans,

就到达另一个希腊营地

而特洛伊人也同样如此

plus neither side completely surrounds the other, peace will prevail.

同时双方的营地 都没有被对方完全包围时

和平就可以持续下去

Anyone can move to a horizontally or vertically adjacent camp,

任何人都可以到达 水平或垂直相邻的营地

but never diagonally.

但不能走对角线

The problem is, they’re currently arranged like this.

问题是，营地现在是这样排布的

Tonight, you can use your powers to swap up to six pairs of camps

今晚，你可以用你的力量 去交换最多六对

that are horizontally, vertically, or diagonally adjacent.

水平、垂直或者对角线相邻的营地

No camp can be moved more than once.

每个营地只能被移动一次

Which swaps do you make to keep the peace?

为了维持和平 你会选择哪些营地进行交换？

Pause here to figure it out yourself. Answer in 3

[暂停一下，自己动动脑] [倒计时：3]

Answer in 2

[暂停一下，自己动动脑] [倒计时：2]

Answer in 1

[暂停一下，自己动动脑] [倒计时：1]

The first insight here is to divide this into two sub-problems.

这个问题可以先被划分成两个子问题

There’s the matter of connecting 4 clumps of Greeks

首先要在不打断特洛伊营地线的同时 把四大块希腊营地连接起来

without putting holes in the Trojan line.

And then there’s dealing with the thorny center space.

然后是处理棘手的中心区域

Let’s consider the Greeks first.

让我们先来考虑希腊营地

To connect any Greek clumps,

要想把任何两大块希腊营地连接起来

you’ll have to mess with the nice, straight Trojan lines.

都要打断那些漂亮笔直的特洛伊营地线

If you try to do that anywhere in the center of these arms,

如果你试图在四条营地线的 中间位置这样操作

you'll create new isolated clusters of Trojans.

你会创建出一块孤立无援的 特洛伊营地群

So the only option is to go to the perimeter of the field

所以唯一的选择就是移动末端的营地

and move some Trojans diagonally, say here, here, and here.

对角线移动一些特洛伊营地 比如这里、这里和这里

Now for the center.

现在来看中心区域

there’s no way to connect the Trojan arms without swapping a Trojan in.

不把特洛伊营地换进来 就无法连接特洛伊营地线

But continuing to shift that arm of Trojans inward

但如果继续把这一端的 特洛伊营地向内移动

would require moving the same Greek camp multiple times.

就需要多次移动同一个希腊营地

However, you could shift the whole Trojan arm up and to the right,

然而，你可以将这一端的特洛伊营地 整体向右上方移动

closing this gap.

把空缺补齐

There are several solutions with slight variants,

有几种略微不同的解决方案

but as long as you perform this maneuver on the short arm of Trojans,

但只要你在特洛伊营地线 较短的那一端执行这个操作

you can achieve peace in exactly 6 moves.

就可以用刚好六次移动来获得和平

You make the swaps and all is well until the fifth night.

你交换了营地，一切顺利 直到第五个晚上

One of your rival gods wants to see the bloodshed continue,

你的一个敌对神 想让这场血腥之战继续下去

and has taken advantage of a forgotten prophecy.

利用了一个被遗忘的预言

He’s convinced one Trojan camp to make a swap

他说服了一个特洛伊营地

with their horizontal, vertical, or diagonal Greek neighbors

与同它水平、垂直或对角线相邻的 希腊营地进行交换

that will break up the Greek connectivity.

这个交换会打破希腊营地的内部联结

Once again, you consult the Fates, who prophesize the following:

你再一次向命运三女神求助，她们预言了以下内容：

the meddling Trojan camp is somewhere within four grid spaces

捣乱的那个特洛伊营地就在 距离战场边缘四格的范围内

of the perimeter of the battlefield.

They won’t go through with a swap if it only breaks up Trojan connectivity.

如果只是中断特洛伊营地的连接 他们就不会进行交换

And finally, you can make at most two swaps

最后，你最多可进行两次交换去阻止它

with the same rules as before to thwart them.

其余的规则都和之前一样

Which swaps do you make to block the troublesome Trojan camp?

为了阻碍那个捣乱的特洛伊营地 你会选择哪些营地进行交换？

Answer in 3

[倒计时：3]

Answer in 2

[倒计时：2]

Answer in 1

[倒计时：1]

You won't be able to identify the scheming camp precisely,

你无法准确地识别出那个密谋的营地

but there’s a lot you can do to at least narrow down the options.

但你至少可以缩小选择的范围

They have to be somewhere in this area.

那个营地一定在这个区域内

And they have to be able to block Greek camps from each other in a single swap.

它只进行一次交换 就能够打断希腊营地之间的联系

That doesn’t leave many options;

这样一来，剩余的选择可就不多了

the only possible blockages are at the end of these two arms,

唯一可能造成阻碍的营地 就在这两翼的末端

where a Trojan camp could plug a hole without opening a new one.

在这里，特洛伊营地 可以把两块希腊营地隔开

同时不产生新的连接点

So they must be in one of these four camps.

所以捣乱的那个营地一定在这四个之中

Let’s look at the right arm first.

我们先来看右端

There’s a threat here because this column has two Trojan camps.

这一列有两个特洛伊营地 可能会造成威胁

If one moves to the right, the other will still be in place,

如果一个营地向右移动 另一个即使留在原地

blocking Greeks from crossing.

也仍旧可以将希腊营地隔开

so we can thwart them by moving either one a column left into this square.

为要阻止，可以把这两者之一 向左移动一列，放在这里

and the same principle applies to the bottom arm.

这个原理同样适用于下端的营地

Your effort maintains the peace for the final 5 days.

你的付出维护了最后五天的和平

But it seems that a certain Greek general noticed what was happening

但似乎有一位希腊将军注意到了这件事

and left the Trojans a parting gift...

并给特洛伊人留下了一个告别礼……