Since the training camp for the first time as a little bit like the state today, commendable Kazakhstan. Overall I feel this is really konjac considered good.
Do is question the group B.
Attach exam Links: http://120.77.82.93/senior/#contest/problems/2832
The first look at the problem will not pay directly violent water 60 orz exam ..
See this second question : 70% of the data N <= 100
Hey this is not right to give away 70 points. But still seriously thought for a moment it hit the tree line, after all, have been when the monster is not very plausible .. Fortunately, the ac.
How much time do third title gone, the water can not water (how could I say that is because they never learned graph theory), can not be submitted.
The fourth title after a glance that might prove to be cyclical (??), and later feel sure it will not be hot water ah. So hastily called naive to not do violence, tle take thirty.
After the examination of the first questions people have nothing to do with the positive solution of (embarrassed to live).
Some people used to optimize the O2 a, and some O (n ^ 3) even before. .
It appears to be pot Jizhong evaluation machine. .
Solutions should be positive (n ^ 2) each traversing a slope between two points, it is divided into two stacks by positive and negative with O, and then with O (logn) slope level to find a match.
The second question is indeed a tree with a line segment. My approach is to keep it in each unit include a section where: the number and the sum of the numbers, all the numbers of minimum and maximum values min max This way, you can find the need to use O (logn). Sort (discard) the number of min or max, and selectively coupled to answer the same parent node, you have to give up the range of where the sum.
The third question. . This is not even written explanations chiefs eh. 贝尔福德曼 algorithm also O (n³), I kneel.
For more, you can get to know a data structure called cactus
On a list of what knowledge ⑧. Thoughts of the right side pivot point, the tree component DP or tarjan bis Unicom
The fourth question, after listening to others talk about the talk I can conclude that this is a math problem.
You may need to use fast power, torque multiplication, Fermat's little theorem.
Although I state quite good, today's topic is no moisture in it!
Still work hard as well.
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