[332.Reconstruct-Itinerary](https://github.com/wisdompeak/LeetCode/tree/master/DFS/332.Reconstruct-Itinerary) (H)

[753.Cracking-the-Safe](https://github.com/wisdompeak/LeetCode/tree/master/Hash/753.Cracking-the-Safe) (H)

[787.Cheapest-Flights-Within-K-Stops](https://github.com/wisdompeak/LeetCode/tree/master/Graph/787.Cheapest-Flights-Within-K-Stops) (H-)

[1192.Critical-Connections-in-a-Network](https://github.com/wisdompeak/LeetCode/tree/master/DFS/1192.Critical-Connections-in-a-Network) (H)

1334.Find-the-City-With-the-Smallest-Number-of-Neighbors-at-a-Threshold-Distance (TBD)

1361.Validate-Binary-Tree-Nodes (TBD)