A. Star Trek
First, the
to sum up
$ T1 $ Euler did not expect, first with $ tarjan $ shrink a point,
First, think of the examination room $ tarjan $ shrink into a forest after completion point,
For each node of the forest, which is connected to the side and the $ 2 $ selected, and thus updated,
The last sentence loopback, loopback $ a $ 2, $ 1 $ 1 $ $ a loopback edges.
Then ring the leaf nodes of the tree if there is greater than $ 2 $ edges, then its contribution is only $ 2 $, (I did not know how to think)
Final tally $ ans $ output. .
$ T2 $ See this question thought half. . .
Binary code again, the sample directly over, feel right, I did not expect it not monotonic. . .
The last $ 20 $ points (half but others are $ 30 $ ......)
$ T3 $ no idea,
Hit it again $ dfs $, he went to $ 4 $, and finally began to run $ 5 $ point, ran for about half an hour. .
Such lured $ 15 $ points. .
Finally, $ 20 + 0 + 15 = $ 35. (The first question directly $ cout << 0 $ $ 20 $ can get and I burst zero)
Nothing levels. . .