Cf #254 Simplified Chinese topic

Here is a more detailed explanation of XYZ. Just translate it.

Div2a parity Dyeing

Div2b considers contribution to the answer 2 ^ (n-number of connected blocks)

When div1a is optimal, only one side can be selected using the reverse identification method, considering splitting the exported subgraph.

Div1b statement: the number of attacks ranges from large to small, and the number of attacks ranges from 1 to 1.

Div1c XYZ training team paper

The div1d query strings contain brute force attacks that occur frequently, and are merged when the number of attacks is small.

Div1e looks like question E. The solution is to divide the answer into two parts and then split the network flow chart to run fast. [then, it was found that DSU sorting was too complicated .]