444. Sequence Reconstruction

Solution idea

Topological Sort

要点总结

1. When does Topological Sort gives uniquely sorted array?
   • if there is > 1 nodes at same level (degree == 0), then sorted array is NOT unique
   • 如何判别？queue 每时每刻都只会有一个元素，每 pop 1个元素，它只会 enqueue 1个元素

Time complexity = $O(V+E)$

Resource

wisdompeak/LeetCode