JSOI2015 a round of provincial election

Source: Internet
Author: User

T1:

a tree with a root node of 1 is required, starting from 1, passing the following points and eventually going back to the root node. At the same time, in addition to the root node all points have a weight (that is, benefit, each point on the proceeds can only be taken once, and after that must be taken), at the same time, in addition to the root node has a number of times limit, ask to find out from the root node to the root node of the ultimate benefit sum of the maximum And whether there are many ways this maximum can be done (the simple access Order is different)

The main problems : very obvious tree-like DP, about each node is transferred, take the most front of some (note the negative words regardless of how directly ignore, but 0 do not throw directly), and then take the largest sum can be (recommended with a heap what maintenance, direct reckless afraid of tle, Anyway, I usually go directly to the left-leaning tree. The next step is the transfer of multiple solutions--in this case, there are three situations where there are multiple solutions: 1. The number of sub-nodes that are taken is more than one solution (this is obvious) 2. After the current point has been taken, there is a point in the point where the value is 0 (it is obviously advisable not to take it.) 3. After the point is taken, it is found that the minimum value of the point taken is the same as the maximum value of the point not taken (it means that since you can choose this, you can also choose that) the other has not, the tree-like DP mess to engage in AC

Note: This problem is due to take into account some details, so it is estimated that most people kneel in detail-so-for their own problems, cherish it-after all, I wait Konjac Konjac can be the province of the topic will not be too much

Personal Procedures points (Pascal)

T2:

Main topic: to a 01 square matrix, find the largest square sub-matrix to meet 8 yuan symmetry (4 axis of symmetry), 90 degrees symmetry (turn 90 degrees, turn 180 degrees, turn 270 degrees can coincide), 4 yuan symmetry (2 vertical axis), 180 symmetrical axis (turn 180 degrees can coincide), The sub-matrices of simple symmetry (1 axes of symmetry) become longer

The sum : This one... No one seems to be successful AC, so I also spent 5 minutes to write an O (n^5) of violence (although obviously far less than, the actual value of probably O (n^4) appearance), the results of the miracle happened--70!!!! (Listen to star God Ben said in two points, details do not know Orz OTL)

Note: seems to stretch the tree teacher (Hey Hey heh: stretch tree èsplayèspl there are wood!!! That's right--a miracle!!! For this can write violence of the topic do not write white do not write (but obviously can not write also white write) Orz Orz Orz

Personal Procedures 70 points (Pascal)

T3:

The main idea : for a non-directed tree, first remove the useless point (the useless point is the point of 2 points, remove the useless point is to point to the left side of the useless points directly to join together, thus ignoring this useless point), Then judge whether the remaining tree is the same as the shape (the same thing is a bit like judging the homogeneous heterogeneity of organic matter, but the hands-type atoms do not need to consider).

The solution : Well, although I am a certain sense of AC, but in fact, my mess-the method is as follows, first to clean useless points, and then for two trees, the first contrast point is not as much (obviously), followed by the degree of each point is likely to correspond, and then meet the following conditions , I used a very funny way--for two trees, peel off the outermost layer of the leaf node (the point of 1 degrees), and then see if it is removed as much, if not the same directly can be judged to be different; then continue to peel a layer, and then look at the same layer to peel, and then to peel until the bare-Ben , if each wave is stripped down the same, then these two graphs are the same (in fact, I was inspired by the chemical isomer judgment--to determine whether an alkane is isomorphic, we will generally ignore the H atom, right? And then, in fact, this time there may be more complex diagrams, so why not consider stripping the carbon chain once again as intact organic matter? Is that right? Although I will not be correct, but still mixed with the jsoi of the 10 groups of data (Jyy said the positive solution is a hash, it seems a bit reasonable)

Note: this question ... Alas... Think of want to cry--rare to make a difficult problem, the result is actually tease-the output format is wrong, alas ... Otherwise I am 270 first in the province, and compared to the highest score of 210 is sadistic ... Alas... To make a life worse than to ruin it. Or that sentence-cherish the idea of the topic, after all, not many

Personal Procedures ( Pascal) (actually the problem is zero, because the output format is a tease)

Summary: The first round has ended, because I last round noip serious tease reason, so the province ranked only 30 appearance, but also basically and the last round 500 up and down the small partners equaliser, refueling-continue efforts. At the same time, it is worth noting that I can make good progress or play, and I have always felt too weak, has maintained a sense of hardship is quite relevant, I hope this small victory not to disrupt the rhythm of my progress-to stop my own people, only myself, can bless my own people, but only myself. The most important point is-less tease, the topic tens of millions to see clearly, this time wrote 12kb the correct program results finally dog blood died in the output format is also drunk, I wait Konjac Konjac will be the provincial topic after all limited, or cherish it-in fact, this seemingly T1 can ac (personally feel more water), T2 earnestly write O (n^5) of violence (it turns out that as long as you do not tease than at least 60 can get), T3 This problem is purely fortunate this time (lqybzx: hehe funny than also called lucky? Hansbug:tt, but say the highest score only 210 I 170 in the heart is also a basic balance of the DA), in the next two rounds are estimated to only water a 10-30 of the violence ... This is the way, continue to work hard, not to be happy with their own sorrow is

JSOI2015 a round of provincial election

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