I personally believe very handsome abstract graph theory, once the problem to the point of abstraction, graph theory algorithms to run on it.
I was abstract graph theory pit many times, this question is a good question exam questions && brush, do not waste. I remember there portal, running water, a few pieces this abstract graph theory.
Look out next time he is about to leave abstract graph theory graph theory summarized. .
This is a little problem I have no idea.
We start from the analysis of the status bar.
The problem is that a point only one state it. I never thought of it in the examination room, according to a direct consideration.
Then I would not let Yuki how come let lilulu over. To update the answer.
Such considerations will be very complicated.
We consider each point from the state, if the point is really the point, so really only one state,
However, (x, y) is not a point, which is the location of manifold is made.
So there are two states, one after a pass from the Qi in the air to the ground.
There are point to point distance, for example, to throw past, we must consider the open look contribution, or direct that n ^ 2 regardless of space or time.
For example: a * L + b, it should be said, as a walk of L + b step down.
So to ensure that each point to build only side to side.
And then found up and down about four o'clock this could turn are built, then you can continue to divide the state to limit the transfer.
Another problem is how to stop when none Lulu ran?
Deal directly with the closest distance to each point of interest Lulu on the line.
This applies to: Lee Lulu only after each one, then I was flying when every other point closest distance will not change.
This ensures chart graph theory unchanged.
So the method came out. No longer.
Difficulty of this problem is still considering the construction diagram.
Abstract graph theory to do more of it.
Many would like to think when things do not spend one second to ask what is not right.
In a lot of nature when I first saw the title I think it is wrong, then it is no longer thought about it. Lead to unexpected positive solution.
Then remember Duosi Suo, network flow seniors say ugly out, because the network is abstract flow graph theory.
Bipartite graph, network flow, split points are considered abstract graph theory.