Leetcode 488. Zuma Game

Given a board string and a multiset hand of colored balls, find the minimum number of insertions needed to clear the board by inserting balls that create runs of ≥3 same-color balls which may cascade. The core challenge is exploring the exponential state space of board+hand states while simulating removals and using search with memoization/pruning to find the minimum moves (or return -1 if impossible).