Leetcode 656. Coin Path

Given an array of coin costs (with some positions possibly blocked) and a maximum jump length B, find a sequence of jumps from the first to the last index that minimizes the total cost; if multiple sequences have equal cost return the lexicographically smallest index sequence, or empty if unreachable. This is essentially a shortest-path/DP on a directed acyclic graph with a lexicographic tie-breaker constraint.