P10050 [CCO 2022] Alternating Heights

Troy plans to take a group photo of the CCO students, and he asks you for help. There are $K$ students, numbered from $1$ to $K$. Troy forgot the students' heights, but he remembers that no two students have the same height. Troy has a sequence $A_{1}, A_{2}, \ldots, A_{N}$, representing the order of students in the photo from left to right. A student may appear multiple times in $A$. You are not sure how this photo will be taken, but you do not want to believe that Troy made a mistake. Troy will give you $Q$ queries of the form $x, y$. Each query asks: "Given the student sequence $A_{x}, A_{x+1}, \ldots, A_{y}$, can their heights form an alternating sequence?" More specifically, let $h_i$ be the height of student $i$. If there exists a height assignment $h_1, h_2, \ldots, h_K$ such that $h_{A_{x}}>h_{A_{x+1}}h_{A_{x+3}}

The first line contains three integers $N$, $K$, and $Q$, separated by spaces. The second line contains $N$ integers representing $A_{1}, A_{2}, \ldots, A_{N}\left(1 \leq A_{i} \leq K\right)$. The next $Q$ lines each contain two integers $x$ and $y$ separated by spaces $(1 \leq x

Output $Q$ lines. On the $i$-th line, output `YES` or `NO`, indicating the answer to Troy's $i$-th query.

## Sample Explanation For the first query, it is impossible to have $h_1>h_1$, so the answer is `NO`. For the second query, one valid assignment for $h_1>h_2h_1$ is $h_1=160 \mathrm{~cm}, h_2=140 \mathrm{~cm}, h_3=180 \mathrm{~cm}$. Another valid assignment is $h_1=1.55 \mathrm{~m}, h_2=1.473 \mathrm{~m}, h_3=1.81 \mathrm{~m}$. For the third query, it is impossible to have both $h_1>h_2$ and $h_1