From preoder condition you can sort the number of trees using 2nC_{n}/(n+1) n
Total trees = [2nC_{n}/(n+1)]*n! = 30 (n = number of distinct labeled nodes.)
To sort them from preorder condition use = [2nC_{n}/(n+1)] = 5 trees which matches the given preorder conditions.
Now draw them and sort according to postorder. (out of 5 you will get 4 with matching given conditions)
A
B
C
A
B
C
A
B
C
A
B
C
i haven't found any other way except this.