Add WordTree data structure and helper functions

src/boggler/c/boggler.c

@@ -3,6 +3,7 @@
 #include <string.h>
 #include <ctype.h>
 #include "board.h"
+#include "tree.h"
 
 int main(int argc, char **argv) {
     const uint8_t BOARD_SIZE = 4;
@@ -17,9 +18,20 @@ int main(int argc, char **argv) {
     struct BoardCell **cells = malloc(sizeof(struct BoardCell*) * BOARD_SIZE * BOARD_SIZE);
     for (uint8_t i = 0; i < BOARD_SIZE * BOARD_SIZE; i++) {
         cells[i] = create_board_cell(letters[i], (int)(i / BOARD_SIZE), i % BOARD_SIZE);
+        print_boardcell(cells[i]);
     }
 
     Board board = { .height = 4, .width = 4, .cells = cells };
     print_board(&board);
     free(cell_letters);
+
+    struct WordNode *root = malloc(sizeof(struct WordNode));
+    init_wordnode(root, false, cells[0], NULL, NULL, 0);
+    print_wordnode(root);
+    add_child_node(root, cells[5], false);
+    //add_child_node(root->children[0], cells[6], false);
+    print_wordnode(root);
+    print_wordnode_path(root->children[0]);
+
+    free(root);
 }

src/boggler/c/tree.h

@@ -0,0 +1,75 @@
+#ifndef WORD_TREE
+#define WORD_TREE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "board.h"
+
+struct WordNode {
+    bool is_word;
+    struct BoardCell *cell;
+    struct WordNode *parent;
+    uint8_t child_cnt;
+    struct WordNode *children[];
+};
+
+struct WordTree {
+    char *alphabet;
+    struct WordNode *root;
+};
+
+void print_wordnode(struct WordNode *n) {
+    printf("%3s | (%d,%d) | %3d\n", n->cell->letters, n->cell->row, n->cell->col, n->child_cnt);
+}
+
+void *print_wordnode_path(struct WordNode *n) {
+    if (n == NULL) {
+        return NULL;
+    }
+    struct WordNode *node = n;
+
+    // Print letters from leaf to root
+    do {
+        printf("%s < ", node->cell->letters);
+        node = node->parent;
+    } while(node != NULL);
+    puts("ROOT");
+    return node;
+}
+
+void *init_wordnode(struct WordNode *n, bool is_word, struct BoardCell *cell,
+    struct WordNode *parent, struct WordNode *children[], uint8_t child_cnt) {
+    n->is_word = is_word;
+    n->cell = cell;
+    n->parent = parent;
+    if (children != NULL) {
+        for (uint8_t i = 0; i < child_cnt; i++) {
+            n->children[i] = children[i];
+        }
+    }
+    n->child_cnt = child_cnt;
+
+    return n;
+}
+
+struct WordNode *add_child_node(struct WordNode *parent, struct BoardCell *cell, bool is_word) {
+    parent = realloc(parent, sizeof(struct WordNode) + sizeof(struct WordNode*));
+    parent->children[parent->child_cnt] = malloc(sizeof(struct WordNode));
+    init_wordnode(parent->children[parent->child_cnt], is_word, cell, parent, NULL, 0);
+    parent->child_cnt++;
+    return parent->children[parent->child_cnt];
+}
+
+void *insert_word(struct WordTree *tree, char *word) {
+    // TODO: Traverse tree from tree->root and add nodes needed to complete `word`
+    return NULL;
+}
+
+
+int search(struct WordTree *tree, char *word) {
+    // TODO: Traverse `tree` node-by-node and return an array of Board paths for `word`
+    return 0;
+}
+
+#endif /* WORD_TREE */