Can anyone tell me, why this implementation of trie

#define M 100111
struct NODE {
    char c;
    int v;
    NODE * next;
} * trie[M];

uses about 5 441 KB at Timus?
I use about 1 MB of additional arrays, but anyway it is too much.

Input text is < 100 KB => size( trie[M] ) <= 1 MB!

Please, help me!
Maybe admin can say something?
Maybe it is because of using heap?

How do you use this implementation? What does "next" mean?