A. solution of equation
to sum up:
The exam brain feels wrong. . .
Look up $ T1 $, a board exgcd $ $?
$ 20 $ minutes played a violent, then he pushed a little formula, did not begin to take the examination left $ 1 $ hours when playing for a shot.
I found a lot of mistakes, plus a bunch of special sentence. . Finally did not increase enough. . $ 80 $ points.
$ T2 $ glance, think of the number of Cattleya.
Finally, always wanted to push the number of combinations, and has been wrong. . Finally, $ QJ $ test points to get $ 10 $ points.
Then he skipped. .
Looked at T3 $ $, $ apparent $ DFS can get most of the score, then skipped. . . He began to push $ T2 $ formula. (I do not know how to think)
Then fast $ 9:40 $ when it began to code $ T3 $,
The sample code after this last group of water directly before. .
In fact, the middle is wrong. . Finally, the inevitable $ WA 0 $.
Exam changed a bit and then get the normal $ 60 $ Score,
So finally 80 + $ 10 + $ 90 = 0.
Nothing levels. . .