Minimum Operations to Form Subsequence With Target Sum

Given an array of powers of two where you can replace any 2^k with two 2^(k-1) at cost 1 (the halves are appended to the array), find the minimum number of such splits so that some subsequence sums to target, or return -1 if impossible. The core challenge is greedily balancing counts of each power-of-two to match the target's binary representation by splitting larger powers as needed.