← All problemsSign in

Maximise Subsequence Value

CodeChefRating 2255Open on judge ↗

You are given a sequence $A_1, A_2, \ldots, A_N$. You should select a (not necessarily contiguous) subsequence of $A$ and reverse it. In other words, if you select a subsequence $A_{i_1}, A_{i_2}, \ldots, A_{i_K}$ ($1 \le i_1 \lt \ldots \lt i_K \le N$), then for each valid $j$, the $i_j$-th element of the resulting sequence is equal to the $i_{K+1-j}$-th element of the original sequence; all other

HINT LADDERno hints yet
L1 Observation
L2 Technique
L3 Approach
L4 Pseudo-code
🔒
L5 Full solution
L5 unlocks only if you insist twice
solution.cppC++17

CodeSearch Tutor

Hints, not spoilers — it won’t hand over the full solution unless you insist.

voice by Sarvam AI

Sign in to chat with the tutor and save your progress.

Sign in to start