/in/foo.cc: In constructor 'Trie::Trie()':
/in/foo.cc:14:34: warning: passing NULL to non-pointer argument 2 of 'void* memset(void*, int, size_t)' [-Wconversion-null]
   memset(next, NULL, sizeof(next));
                                  ^
/in/foo.cc: At global scope:
/in/foo.cc:7:1: warning: 'typedef' was ignored in this declaration
 typedef struct Trie
 ^~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:24:12: warning: unused variable 'j' [-Wunused-variable]
  int n, i, j, k, sum, q;
            ^
/in/foo.cc:24:15: warning: unused variable 'k' [-Wunused-variable]
  int n, i, j, k, sum, q;
               ^
/in/foo.cc:24:18: warning: unused variable 'sum' [-Wunused-variable]
  int n, i, j, k, sum, q;
                  ^~~