please give me some tests.All test that I found in other topic my programm pass.

When the program is launched, the database contains a single word "sun".

>>If the length of the resulting list exceeds 20, then you should output the first 20 names only.


So, this was my mistake, I initially ignored this statement.
Trie with pointers, std::string and std::cin/std::cout gets AC in 0.31 with 10 372 KB used.