Leetcode 1387. Sort Integers by The Power Value

Compute each integer's Collatz "power" (number of steps to reach 1 using x/2 for even and 3x+1 for odd), sort the numbers in [lo, hi] by power (breaking ties by numeric value), and return the k-th element in that order. The range is small (hi ≤ 1000), so precomputing powers for the interval is sufficient.