give root nary tree return postorder traversal node valuesNaryTree input serialization represent level order traversal each group child separate null value see example example 1input root 1null324null56output 563241example 2input root 1null2345nullnull67null8null910nullnull11null12null13nullnull14output 2614117312841391051 ConstraintsThe number nod tree range 0 1040 Nodeval 104the height nary tree equal 1000 Follow Recursive solution trivial iteratively