Problem - Kth Smallest in Range

Given an array, answer queries: "What is the $k$-th smallest element in subarray $A[l..r]$?" Example: $A = [1, 5, 2, 4, 3]$ Query $(0, 3, 3)$: 3rd smallest in $[1, 5, 2, 4]$ is $4$.

You're solving the range quantile problem. Common in database systems for percentile queries. Note: LeetCode has related problems, but this specific online query version often appears in competitive programming.