Bestcoder Round #90//div All-in-one roll-up ladder game, tree array, Gaussian elimination

Bestcoder Round #90

At least three knowledge points exploded at this time ....

A. ZZ question

Press Test instructions copy init function and then count OK

B.

The game problem does not understand the half-day of the SG ..... The result of this question ....

C

Data structure problem I wrote for half an hour and found that the color was changed .... Oh, my God, deep-fried.

D.

I don't know what to do with the topic ... The official puzzle is to kill the little circle.

Bestcoder Round #90//div All-in-one roll-up ladder game, tree array, Gaussian elimination