|
| 1 | +classSolution { |
| 2 | +publicintshortestPathLength(int[][]graph) { |
| 3 | +intn =graph.length; |
| 4 | +Map<Integer,Set<Set<Integer>>>map =newHashMap<>(); |
| 5 | +Queue<State>queue =newLinkedList<>(); |
| 6 | +for (inti =0;i <n;i++) { |
| 7 | +Set<Integer>visited =newHashSet<>(); |
| 8 | +visited.add(i); |
| 9 | +map.put(i,newHashSet<>(List.of(visited))); |
| 10 | +queue.add(newState(i,0,visited)); |
| 11 | + } |
| 12 | +while (!queue.isEmpty()) { |
| 13 | +Stateremoved =queue.remove(); |
| 14 | +intnode =removed.node(); |
| 15 | +intsteps =removed.steps(); |
| 16 | +Set<Integer>visited =removed.visited(); |
| 17 | +if (visited.size() ==n) { |
| 18 | +returnsteps; |
| 19 | + } |
| 20 | +for (intconn :graph[node]) { |
| 21 | +Set<Integer>connVisited =newHashSet<>(visited); |
| 22 | +connVisited.add(conn); |
| 23 | +if (!map.get(conn).contains(connVisited)) { |
| 24 | +queue.add(newState(conn,steps +1,connVisited)); |
| 25 | +map.computeIfAbsent(conn,k ->newHashSet<>()).add(connVisited); |
| 26 | + } |
| 27 | + } |
| 28 | + } |
| 29 | +return -1; |
| 30 | + } |
| 31 | + |
| 32 | +privatestaticrecordState(intnode,intsteps,Set<Integer>visited) {} |
| 33 | +} |