Cheapest Flights K Stops 30 XP Medium

Find the cheapest flight from src to dst with at most K stops. Modified Dijkstra or BFS with level constraint. Bellman-Ford with K+1 iterations also works.

Bellman-Ford: relax all edges K+1 times. Each iteration allows one more stop. Use a copy of prices to avoid using updates from the same iteration.

💡 Pro tip: Understand this problem deeply — don't just memorize the code. Try explaining the approach out loud as if teaching a friend. If you can explain it simply, you truly understand it!