Leetcode 847. Shortest Path Visiting All Nodes

Find the minimum number of steps in a walk that visits every node of an undirected connected graph (n ≤ 12), where revisiting nodes/edges is allowed. This is solved by searching the shortest path in the augmented state space (current node, visited-node bitmask) — typically via BFS/bitmask DP over O(n·2^n) states.