21 analog solution to a problem

A. origami

Consider $ O (nm) $ violence,

For each operation, violence modifications subscript n points,

While maintaining about endpoint index, last subtraction is the answer.

For 40 minutes after, a large range of n.

We do not just focus on each point of the index.

For each folded,

$ O (m) $ query and records the index can be folded when the operation.

Note that each operation can not simply folded in one direction.

In extreme data card may be explosive longlong.

 

 

 

B. Inequality

 

 

 

 

C. reverse