T1:
Category talk, monotonous stack, two points, to maintain some of the array.
This fight for the title shot. When the exam is critical to shoot, investigate some mistakes.
T2:
DP complexity of the explosion.
Positive solution provides a greedy when either DP feasible ideas.
set library maintenance decision, take a small, pop-up big exceeds storage limit.
The difference between greedy and go back is: No contribution is calculated upon accession set, but may reserve a decision.
For Violence 60pts: For each d [i], sweep 1 ~ i, computational costs and sort. + Segment tree minimum interval modification, maintenance, up to a certain point at the storage limit how many.
Similar to the concept of network traffic flow.
T3:
Constructed directly using the title property.
Special is 2 * n + 1.
Each can then be divided into two group.
-1 Bluff, certainly solvable.
a + b may be sorted through, six kinds of sorting the examination room, but did not open the array twice, into pieces 50, KUKU.