Delete a Word from a Trie

#include <stdio.h>
#include <stdlib.h>

struct Trie { struct Trie *child[26]; int terminal, pass; };
struct Trie *new_trie(void) { struct Trie *node = calloc(1, sizeof *node); if (!node) exit(EXIT_FAILURE); return node; }
void insert_word(struct Trie *root, const char *word) { for (int i = 0; word[i]; i++) { int index = word[i] - 'a'; if (!root->child[index]) root->child[index] = new_trie(); root = root->child[index]; root->pass++; } root->terminal = 1; }
struct Trie *walk(struct Trie *root, const char *word) { for (int i = 0; word[i] && root; i++) root = root->child[word[i] - 'a']; return root; }
void free_trie(struct Trie *root) { if (root) { for (int i = 0; i < 26; i++) free_trie(root->child[i]); free(root); } }

int main(void)
{
    struct Trie *root = new_trie(); insert_word(root, "code"); insert_word(root, "coder");
    struct Trie *node = walk(root, "code"); if (node) node->terminal = 0;
    printf("code = %s coder = %s\n", walk(root, "code") && walk(root, "code")->terminal ? "Found" : "Missing", walk(root, "coder") && walk(root, "coder")->terminal ? "Found" : "Missing");
    free_trie(root); return 0;
}